Template:Lesson Summaries 1-20
In a place that looks like a courtroom, MC is confused to suddenly find themselves being welcomed to the Devildom by a man who introduces himself as Diavolo. He goes on to explain he is "the ruler of all demons" and that MC has been brought to the Royal Academy of Diavolo, aka "RAD."
Diavolo then introduces Lucifer — his right-hand man and the "Avatar of Pride" — who explains that MC has been chosen as a representative of the Human World in Diavolo's exchange program, which is a program intended to strengthen the Devildom's relationship with the Human world and the Celestial Realm. As one of the four exchange students joining at RAD, MC will stay in the Devildom for one year while working on school tasks. Lucifer then gives MC a D.D.D. — which functions nearly identical to a smartphone — and tells them to call his brother Mammon with it.
After the phone call, Lucifer introduces his other present brothers: Asmodeus, Avatar of Lust and fifth oldest; Satan, Avatar of Wrath and fourth oldest, and Beelzebub, Avatar of Gluttony and sixth oldest. Diavolo then tells MC they'll be saying with Lucifer and his brothers in the House of Lamentation during their time in the Devildom. Mammon, the "Avatar of Greed" then arrives, and Lucifer informs him that he will be in charge of watching over MC, which Mammon agrees to only after putting up a fight about it.
Lucifer tells MC their task at RAD is to "polish up your soul" and "acquire the power to resist demons." At year's end, MC will also be required to write a paper about their stay in the Devildom. However, as MC has no magic, he and his brothers will lend MC their powers via special cards summoned using the Nightmare app on their D.D.D. and used in dance battles. With his explanation complete, Mammon takes MC to the House of Lamentation, which acts as the dorm for RAD student council members, except for Diavolo, who resides in a castle instead.
Once inside, Leviathan, the "Avatar of Envy" shows up. He demands Mammon pay him back the money he owes, to which Mammon uses MC as a distraction before running off. Leviathan then gets an idea, and drags MC to his room. After rambling for awhile about The Tale of the Seven Lords fantasy novel series — aka "TSL" — and introducing MC to his goldfish Henry, Leviathan tells MC that he want the money back he gave Mammon. However, he can't force him, because Mammon is the second oldest brother while Leviathan is the third, meaning that he's weaker than Mammon.
Instead, he wants MC to make a pact with Mammon, which would mean he'd have to do whatever MC told him, including giving Leviathan his money back. Traditionally, humans entering pacts with demons offer their soul in exchange, but to avoid trading their soul, Leviathan plans to have MC offer something "he'd do ANYTHING to get."
MC has their first day at RAD, where they encounter Solomon, who introduces himself as the other exchange student from the Human World. He hands MC their D.D.D. before departing. MC then runs into Lucifer, who warns them that Solomon cannot be trusted, and that he not only "wields powerful magic," but also has a Ring of Wisdom that aids him in controlling demons.
Going on what Leviathan told them yesterday about Lucifer having Mammon's credit card, MC tries to get a hint from Lucifer about where he hid it. He mentions having "frozen" something of Mammon's, then the bell for the next class rings, and the two part ways.
Meanwhile, Solomon, Satan, and Asmodeus are playing cards and discussing Mammon. Satan comments that he heard from Lucifer that MC is trying to make a pact with Mammon, and has "teamed up" with Leviathan with this goal in mind. According to Satan, Lucifer also said he gave MC a hint about the location of Mammon's credit card.
That night, back in the House of Lamentation, MC receives a chat from Leviathan asking them to come to the kitchen. They encounter Beelzebub there, and ask about the seventh brother they've not seen. Beelzebub doesn't tell them anything, and tells them not to ask his other brothers either, because Lucifer would be angry.
After Beelzebub leaves, Leviathan comes out of hiding. He looks for Mammon's credit card in the freezer, and finds it frozen in a block of ice, which he puts into the microwave to thaw. Mammon then enters the kitchen to sees his card — which he's named Goldie — and begs for Leviathan to return it to him. Leviathan will only agree if Mammon makes a pact with MC, to which Mammon agrees.
In the Dining Room he next morning, Asmodeus and Satan talk about how amusing it is that Mammon now has a pact with MC, and how interesting it is that Leviathan helped them. Mammon enters and starts yelling at everyone for treating him poorly, then blames the whole situation on Lucifer and insults him, not realizing Lucifer had entered the room as well. Lucifer hits Mammon, then compliments MC for having made a pact with him.
Mammon drags MC out of the room, complaining that bad things have been happening to him ever since MC's arrival. After he threatens to eat MC, they use their pact for the first time, telling Mammon to "stay!" Mammon freezes in place, unable to move due to the pact's magic.
Later at RAD, MC is introduced to Barbatos — Diavolo's steward — as well as Simeon and Luke, who are both angel exchange students from the Celestial Realm. After both Lucifer and Diavolo tease Luke by calling him a "chihuahua," everyone save Luke and MC leave for the next class. Luke takes this time to warn MC to "never trust a demon. Especially when that demon is Lucifer."
That night, MC thinks they hear someone calling for help. They leave their room and follow the sounds to the stairs of the attic, where they run into Lucifer. He warns them that the attic is dangerous for humans, and instructs them to return to their room, which they do.
It's another night of MC being unable to sleep at the House of Lamentation, so they try again to reach the attic, and again are stopped at the staircase by Lucifer. In the Dining Hall the next morning, MC asks Mammon what it at the top of the stairs. He initially refuses to say anything, but after some goading, he relents.
He tells MC that Lucifer has an interest in the vinyl soundtrack for The Tale of the Seven Lords. If they can get the soundtrack from Leviathan and give it to Lucifer, that should distract him so that MC can climb the attic stairs. MC asks Mammon to help them, then make use of their pact with him when he refuses.
The two go to Leviathan's room, and are surprised to encounter Solomon in the hallway. He tells them Leviathan invited him to his room, then knocks on the door. He then says a secret phrase related to TSL trivia beginning with "The second lord..." and is allowed inside. When MC tries using the same secret phrase, however, it doesn't work due to the phrase being "periodically reset." Mammon decides this means MC will have to learn enough trivia about TSL for Leviathan to let them borrow the soundtrack.
MC then has a "TSL Full Series DVD Marathon Night" with Mammon and Beelzebub, who is there for the popcorn. They learn in DVD Volume 2 that the Lord of Fools' former sweetheart's name is "Geldie," in Volume 5 that supplies the Lord of Fools sent the Lord of Flies' country had spoiled, and in Volume 7 that the other lords can't free the Lord of Emptiness from his tower because they were afraid of the Lord of Corruption.
The next day, Mammon quizzes MC to make sure they remember this information, the Leviathan shows up. MC challenges him to a competition to see who the bigger TSL fan is, and eventually goads him into agreeing. Later at RAD, both Satan and Beelzebub give MC advice on how to defeat Leviathan. Mammon later agrees with what Beelzebub said about trying to make Leviathan jealous to throw him off his game, but warns that if they succeed "there's no guarantee he won't kill ya."
MC can either ask "a human" or "an angel" for advice on how to make Leviathan jealous, and then it is time for the "Devil's Trivia Showdown." The judge for the competition is Diavolo, Asmodeus is the host, commentary will be given by Satan, and the "guest demon" is Beelzebub, which was paid to be there in cheeseburgers.
The showdown begins, and MC is given easy questions, such as listing the first three lords in order of age — said order being "Corruption, then Fools, then Shadow" — while Leviathan is asked questions such as what is written on page 724 of TSL Volume 3. Despite the difficulty gap, Leviathan still manages to answer every questions he's given correctly. In response, Mammon urges MC to play their "trump card."
To turn the tides of the TSL competition in their favor, MC reveals their "secret weapon." If they chose to ask an angel for advice in Lesson 3-17, MC summarizes the plot of the still unreleased TSL Volume 9, as was told to them by Simeon. Their words are confirmed by Diavolo, who is capable of telling "whether someone is telling the truth," as explained by Satan.
If MC chose to as a human in Lesson 3-17, they reveal a pendant loaned to them by Solomon in the shape of a single wing. This is the platinum version of the Lord of Corruption's lost wing pendant, which is an extremely rare item of TSL merch.
Whichever option was chosen, the advice pays off, and pushes Leviathan into such a fury that he turns into his demon form and charges at MC. He is stopped, however, by Lucifer also taking his demon form and defending MC. Lucifer then orders Leviathan to return to his room and calm down, which he does. Diavolo then announces the competition to have ended in a draw.
MC managed to fall and sprain their wrist in all the chaos, so Mammon joins them in their room and tries his best to bandage it. Beelzebub is also there, which Mammon complains about, but Beelzebub rebuts that Mammon is in MC's room so often he's even left a phone charger and toothbrush here. He then heads to the kitchen for a soda, leaving Mammon alone with MC. He then tells them that he — and no one else — has to be the one to save them next time, and that if he can't save them, "then make sure you die."
MC gets a chat from Leviathan, and leaves to meet him in the Planetarium. While they're gone, Mammon snoops around their room looking for things he can sell. He then talks about being willing to sell even MC if there was profit in doing so. Beelzebub calls his bluff, stating that Mammon likes MC too much to do that. Of course, Mammon frantically denies that claim.
In the Planetarium, despite Diavolo declaring the TSL competition a draw, Leviathan still makes a pact with MC. MC then asks him for the vinyl soundtrack for The Tale of the Seven Lords, and heads for Lucifer's room. Once invited in, they give Lucifer the soundtrack, who then tells MC he will now spend the evening listening to the soundtrack and not leave his room, but reminds them that the stairs to the attic are still off-limits.
Naturally, MC takes this opportunity to climb the stairs anyway. At the top, they see an obstructed doorway, behind which is the person whose voice MC has been hearing calling for help. This person claims to be a human, and tells MC that Lucifer locked him here in the attic. The door is sealed with powerful magic that only the combined magic of Lucifer and all six of his brothers can break. So, the stranger tells MC they have to make pacts with all of them, and that their next pact should be Beelzebub.
The next morning in the Dining Hall, Lucifer asks MC if anything happened last night, then admits he allowed MC to visit the attic, and advises them to forget about that, and focus on surviving the year in the Devildom.
Later that night, MC is in their room when they get a chat from Mammon asking them to meet him in the kitchen. When they do so, Mammon pushes them into eating a custard belonging to Beelzebub. Beelzebub then arrives, enraged because he thinks Mammon ate his custard. He turns into his demon form, and charges at Mammon.
MC, Mammon and Beelzebub are brought to Lucifer's where he lectures them on what they had done wrong. The kitchen has been destroyed after Beelzebub went on a rampage, and since MC's room was adjacent to the kitchen, their room now lacks a wall. Lucifer tells them that MC will be staying in Beelzebub's room for the time being, despite Mammon's objections.
There are two beds in Beelzebub's room; the left belongs to Beelzebub, and the right belongs to Belphegor, Beelzebub's twin brother. Beelzebub tells MC that Belphegor is in the human world as an exchange student along with another demon named Diaval. He also tells them the brothers used to have a sister named Lilith who had been especially close to Belphegor and him. MC later realizes that the occupant of the attic room is actually Belphegor when they find a portrait of him in the portrait room. That night they return to the attic to confront Belphegor, who admits the truth.
The next morning, MC eavesdrops on a conversation between Lucifer and Beelzebub, and learns that the demon brothers were originally angels in the Celestial Realm, but after ending up in the Devildom Lucifer pledged his loyalty to Diavolo. They also learn that there is tension between the brothers due to Belphegor having attempted to stand in the way of Diavolo's dream. MC decides to help Belphegor in order to resolve this conflict.
Later on, Luke messages MC that he's outside the House of Lamentation and he needs to spend the night in MC's room. As MC's room was destroyed by Beelzebub, Luke has to stay with MC in Beelzebub's room. During breakfast, both MC and Beelzebub eat less than usual, wanting to bring food back for Luke. Beelzebub having uneaten food left on his plate causes a commotion between Mammon, Satan, and Asmodeus. On the way back to Beelzebub's room, he and MC find Luke roaming the hallway and looking inside other rooms because being stuck in Beelzebub's room is boring.
Back inside the twins' room, Beelzebub announces that Lucifer is conducting a surprise inspection. He shoves Luke into a closet to hide him, but when Lucifer arrives and orders the closet to be opened, Luke isn't there. He's still gone the next day, though MC and Beelzebub hide this from Simeon when he asks them to take care of Luke until he's ready to come back to Purgatory Hall. Beelzebub and MC search the house but still can't find him. When they reach the entrance hall, they notice the decorative dollhouse of the House of Lamentation has an extra room in it; a room that doesn't exist.
MC and Beelzebub find a secret room that is a copy of Lilith's room back up in the Celestial Realm. When MC asks Beelzebub to tell them more about Lilith, he describes what happened during the Great Celestial War. Mammon suddenly calls MC and tells them to hurry to the underground tomb, which is where Luke is. Lucifer found him there, and is furious at the sight of Luke holding a grimoire. When MC and Beelzebub arrive, Luke accidentally admits Beelzebub hid him in his closet. Lucifer doesn't give Beelzebub a chance to defend himself, and warns that he and Luke should get ready to face the consequences.
MC decides to step between them, shielding Luke and Beelzebub. A furious Lucifer tells them that they can only save one of them. However, MC says they want to protect both. Outraged by MC's reply, Lucifer prepares to attack MC just as everything fades to black. Later, MC wakes up back in the twins' room to Beelzebub calling their name. They ask what happened, and Beelzebub explains that Diavolo arrived in time to stop Lucifer. Simeon took Luke home, who was shaken up but not injured. Beelzebub is also uninjured.
Beelzebub tells MC that he's the one to blame for what happened before, and asks MC why they tried to protect him and Luke. MC either tells him they acted on instinct or that Beelzebub and Luke are important to MC as they're friends. Beelzebub tells MC he wants to do something for them as a thank you, so MC asks him to make a pact with them. Beelzebub asks why to which MC replies they want to impress Lucifer so they help him make up with Belphegor. Beelzebub agrees that he also wants the two of them to make up.
He later takes MC to Hell's Kitchen to eat, but Mammon and Leviathan tag along. MC explains to all of them why they to make a pact with the brothers, and Mammon and Leviathan decide to help. When they return to the House of Lamentation, Lucifer appears and tells MC that their room has been fixed. On the last night staying in Beelzebub's room, he has a dream about Lilith that's different from the nightmare he usually has.
The next morning, breakfast with the brothers is awkward and uncomfortable. Just as MC is about to head off to class early, Lucifer tells them to meet him in the music room. A conversation occurs and Lucifer apologizes for his actions. Shortly after, in the student council room, Diavolo makes the announcement that there will be a retreat held at the Demon Lord's Castle.
Everyone gathers in the entrance hall to get ready to leave for Demon Lord's Castle. Mammon tells MC that there are scary rumors about the castle, like there being an underground labyrinth, but Lucifer interrupts the conversation. He hurries everyone along, as he wants to get to the castle before the angels and Solomon do.
They do manage to arrive to the castle first, where Diavolo and Barbatos greet them. Solomon, Simeon, and Luke arrive shortly after. When the younger angel spots MC, he hugs them, saying he's really sorry about what happened back in the underground tomb. Barbatos then begins to explain how the retreat will work.
First, there will be a tour of the castle to learn about Devildom history, and then Devildom food will be served made by himself. The next day will have a scavenger hunt, food from the Celestial Realm will be made by Luke, and finally there will be a dance held. On the final day, lunch will be Human World food will be made by MC.
Everyone has assigned rooms, and MC is to share a room with Simeon and Asmodeus. Mammon demands a switch with his brother, but Asmodeus refuses, and everyone separates to put away their things. Simeon and Asmodeus have a conversation where the latter exclaims how lucky he and MC are to share a room with him, and that there can't be someone out there who doesn't love him. Satan then arrives and informs them the tour will soon begin.
When they join everyone again, Mammon accidentally reveals that he, Solomon, and Satan plan to collaborate together, as Mammon wants to steal things, Solomon wants some magical items that belong to the Demon King, and Satan "just want to give Lucifer a black eye." Of course Lucifer overhears, and tells Mammon that he expects him to come to his room later.
The tour guide is a tiny demon named Little D. No. 2, who is one of the Little D.'s that helps MC in their tasks. First on the tour is the portrait of the current Demon King, Diavolo's father. Luke comments he last saw the Demon King at a ceremony over 1,000 years ago, and Diavolo mentions he hadn't seen his father in several hundred years, as he's slumbering at the bottom of the Devildom.
While passing through the stairways, Helene, a witch trapped inside a painting, recognizes Asmodeus. Number Two explains that when Helene was in the human world, Asmodeus seduced her and she betrayed her lover at the time, leading to a war that destroyed an entire country. She uses what magic she still possesses to pull Asmodeus, Mammon, Leviathan, Beelzebub, Solomon, and MC into the painting.
MC wakes up to Solomon's calls and finds out they're alone in an underground labyrinth. Solomon summons Asmodeus using their pact, and the three of them soon find the others being chased by a giant snake that was once Leviathan's pet named Henry 1.0.
The snake pursues them, but Solomon amplifies Asmodeus's power, who then charms Henry 1.0., and he shows them to the exit. Afterwards, they explain to everyone how they escaped while eating Barbatos's delicious food.
Later that night, Mammon shows up in MC's room and wants to have a pillow fight. However, Lucifer arrives and overhears Mammon when he insults him, so he drags him away.
The second day of the retreat arrives. Mammon didn't get any sleep last night due to Lucifer, and the rest of the brothers have fun guessing what Diavolo had said. The itinerary for the day is a scavenger hunt, so each group is given riddles to solve to find a historical item in the castle and take a picture of it. However, with Asmodeus sabotaging things, Luke's group is not able to complete their riddle solving.
Asmodeus eventually leaves so that he doesn't have to hear Satan's lecturing, and MC follows. They try to make a pact with Asmodeus, but he replies that he'll agree only on the condition that they get a picture of Lucifer's sleeping face.
Later, Luke serves dishes from the Celestial Realm that he made for dinner, and MC tries to get a hint of where Lucifer's room is. After dinner, Diavolo transforms the Hall and fills it with guests from across the Devildom for the formal dance. The demon brothers and Diavolo transform into their demon forms. Mammon nervously asks MC for a dance, but then Lucifer appears and tells MC to dance with him.
As Lucifer and MC dance, he asks them what it is they are plotting. He warns MC that if they ever seem to be a threat to Diavolo or his brothers, he will show them no mercy. Solomon then appears and invites MC to dance. He comments that while MC may have pacts with demons, they don't have the power needed to command them. So, Solomon uses a spell to lend MC some of his powers for the next six hours.
Later that night, MC, Mammon, Leviathan, and Beelzebub commence 'Operation Photograph Lucifer Sleeping'. When they enter what is supposed to be Lucifer's room, they find Cerberus instead. Everyone escapes through a door, only to fall back into the underground labyrinth with Henry 1.0.
Using Solomon's borrowed powers, MC summons Asmodeus to again tame Henry 1.0. Like Solomon had before, they use a spell to enhance Asmodeus's charm. Asmodeus comments that MC is both able to draw more power out of him than Solomon ever has, and seems to have more magical power than he does.
When the four return to the castle, Lucifer explains that if someone tried to get into his room without knocking, they're transported straight to Cerberus instead. Even though MC failed to get the photo of Lucifer, Asmodeus is impressed by their magical powers and decides to make a pact with them.
Later that night in their shared room, Asmodeus is fawning over MC when Mammon suddenly appears. Satan, Leviathan, Luke, Solomon, Lucifer, and Diavolo soon show up as well. Annoyed at Asmodeus's proximity to MC, Mammon throws a pillow in Asmodeus's face, starting a pillow fight. Once the pillow fight ends and everyone goes to bed, Diavolo and Lucifer discuss MC's pact-making in the garden, while Satan is caught by Barbatos eavesdropping on the conversation.
The last day of the retreat, everyone but Lucifer and Diavolo — who are still asleep — wake up late in the afternoon, tired from staying up all night for the pillow fight. Food from the Human World is served for brunch, with dishes made by MC, Barbatos, and Solomon. Asmodeus is avoiding eating anything Solomon made, and as each of the others try Solomon's food, they understand why. Despite looking delicious, the dishes Solomon made taste terrible to everyone except Solomon himself.
Returning home to the House of Lamentation after the retreat, Asmodeus asks MC why they want to make a pact with all the demon brothers, to which MC responds that they want to earn Lucifer's respect. Lucifer asks what the point of earning his respect is, and what MC is trying to accomplish. Satan then states that he's decided he will also be making a pact with MC, which starts an argument that results in Lucifer telling Satan to get out of the house. Satan declares that he would be happy to leave, and goes to his room to pack.
Afterwards, everyone except Satan and Lucifer meet up in MC's room, where MC explains the plan to get Lucifer to make up with Belphegor. Beelzebub points out that earning Lucifer's respect won't work if Satan makes a pact with MC just to spite him. MC asks why Satan hates Lucifer, and Mammon explains that after the Great Celestial War, Satan was born from Lucifer's Wrath, and that while they all raised Satan, he was especially influenced by Lucifer.
MC then goes to Satan's room, where Satan is trying to decide which books to take with him. He warns MC of one book in particular, as it's a forbidden book that causes people to switch bodies. He then explains to MC that he is considered the "fourth-born" because the Demon King gave him and his brothers their names after arriving in the Devildom in the order of most to least powerful. While he was the last born of his siblings, he's the fourth strongest.
Satan then tells MC to make a pact with him, but MC disagrees with Satan making a pact just to irritate Lucifer, and refuses. This angers Satan, and he threatens MC, but is stopped by Lucifer. The two begin arguing, and as Satan's wrath grows, books in the room start to fly off the shelves. Lucifer grabs one of them at the same time Satan does, and in a flash of white the two switch bodies.
Satan (now in Lucifer's body) states that the effect of the body switch lasts for several days. Lucifer (now in Satan's body) still insists they go to school like this, for he does not want Diavolo asking questions. He also wants to keep an eye on Satan while he's in his body, so the two decide to stay in MC's room.
Once in MC's room, with Mammon and Asmodeus still present, Lucifer discusses how things will work. Neither he nor Satan are allowed to go into each other's rooms unless the other is present, and each will avoid doing anything that might attract attention while at school.
The next day, Lucifer, Satan, and MC run into Diavolo, who asks why Lucifer didn't visit the assembly hall first thing in the morning. Satan poorly impersonates Lucifer, but Diavolo reveals that he could tell Lucifer and Satan had switched bodies from the start. He then reminds Lucifer that he has to give a speech to the student body the day after tomorrow. Lucifer concludes that if they haven't switched back by then, Satan would have to deliver the speech as himself.
After school in MC's room, Satan — now joined by Leviathan and Beelzebub — continues to mock Lucifer with bad impressions. MC goes out into the hall to find Mammon hanging from the ceiling, and helps him down only after he agrees to help Satan and Lucifer make up.
In Leviathan's room, Mammon shows MC a game named Dogi✩Maji✩Memorium. Anyone who registers to play is actually pulled into the game world. Mammon plans to have Satan and Lucifer work together toward a common goal while playing the game. Lucifer, Mammon, Leviathan, Satan, and MC enter the game.
Once inside the game, MC and the others find themselves in a Human World school. Leviathan explains that Dogi✩Maji is a school dating sim; one character is designated the "heroine" (regardless of their gender), and the others have to increase their favorability score with them. In this case, the heroine role is played by MC. In the end, one of the players go up to the Roof of Legend and profess their love for the heroine. If the heroine accepts, they win the game.
Lucifer and Satan — now in their own bodies — challenge each other to see who will raise intimacy with MC first, and the game begins. One by one, MC interacts with each of the brothers, which affects their intimacy levels.
While MC is busy elsewhere, Lucifer, Mammon, Leviathan, and Satan hold a meeting. They discuss the fact that winning the game isn't guaranteed, so they have a brainstorming session on strategies to best raise intimacy with MC.
On the final day where the players must profess their love to the heroine, Satan apologizes to MC for getting them caught up in a weird business. If MC tells him to wait, they say that Lucifer doesn't see Satan as a child, and that he only behaves as he does because he wants to look good in front of Diavolo.
On the rooftop, instead of a love confession, monsters start appearing all over the school and the game has into an ultra-hard survival fight. Leviathan seems to be excited about the crazy plot twist in a simple dating sim. The last boss appears, and looks like Cerberus, but Satan states that it's not the real Cerberus. Cerberus charges toward Satan and is about to strike, but Lucifer commands Cerberus to sit, and warns him not to harm his brother. Cerberus obeys, and the screen states that the Mission is Complete.
Back in Leviathan's room, Satan and Lucifer again have their bodies switched in the real world. However, the two brothers seem to have an agreement begun to accept one another.
While all of this was happening, back in the House of Lamentation, Asmodeus and Beelzebub are looking for MC. As the two are cleaning up Satan's room, they touch the forbidden book and switch bodies. Beelzebub (in Asmodeus's body) comments how he doesn't feel hungry, and Asmodeus (in Beelzebub's body) states that he feels incredibly hungry and considers eating some of Satan's books.
Before he does so, both brothers suddenly return to their respective bodies. The forbidden book looks worn out, and Asmodeus states that the more it's used, the more worn out it becomes, until it eventually can't be used anymore.
While shopping in the Devildom, Lucifer — who's still in Satan's body — MC, and Mammon speak about the speech Lucifer has to make tomorrow. They then stop at Hell's Kitchen, where Lucifer treats them all to a meal, but afterwards reveals he did so that Mammon and MC are now in his debt.
Lucifer want to go to the Human World and find the witch who created the curse of the body switch in order to lift it. At first Mammon is excited about going to the human world, but then changes his mind once he heard witches are involved, because he's afraid of them.
There is an obstacle in the way of the trip, however: only certain demons can travel to the human world directly. Because Lucifer is in Satan's body, the magic circle that acts as a doorway doesn't recognize him, and so they can't travel. Satan then arrives and decides to help them, as he's in Lucifer's body, which means the magic seal lets him pass. Thus, they travel together.
In the human world, Mammon's attitude changes again and he enjoys himself. At Victoria Station, Lucifer buys four matching keychains for the entire group, which surprises Mammon, even though it was what he wanted. Once they board the train and are in a private cabin, Mammon leaves to find the dining car so he can take a picture of the food and brag to Beelzebub. However, he stumbles into the wrong room, and suddenly gets accused of a woman's murder. Lucifer, Satan, and MC arrive at the scene after hearing the woman's last scream.
The brothers and MC meet Lucas, Sophia, and Noah, who were all in the company of the dead woman, who happened to be Grisella, the witch the group was searching for. Lucifer uses his powers to hypnotize the three humans so that they leave.
Back in their own car, everyone hears the ghost of Grisella, who wants them to solve her murder in exchange for lifting the curse of the body switch. All the demons want to torture the three suspects, but MC wants to find a less violent way. They question Grisella and Mammon, and with the information Mammon gives, they guess who the killer is. As the three humans from earlier gather, the witch warns MC about Lucifer, saying he'll soon lose the trust he puts in them.
Once in front of the suspects, Satan decides to explain MC's thoughts, and then declares that the killer is Noah. He turns out to be right, as Noah says he truly wanted to become Grisella's apprentice, but the witch had refused him. She didn't want to take Noah as an apprentice because she predicted she'd die in the train, which would break the man's heart. Ironically, her refusal is exactly why she was killed.
Back in their car, Grisella keeps her word and lifts the curse of the body switch. Surprisingly, Lucifer asks Satan to still do the speech about the report he's supposed to do tomorrow, and his brother agrees with confidence.
At Ristorante Six, Lucifer proposes a toast with everyone — save Leviathan, who is absent — for lifting the curse that had he and Satan in each other's bodies. Diavolo thanks MC for how happy Lucifer is, and comments that the right choice was made having MC as an exchange student. MC asks Diavolo how they were chosen in the first place, and he explains that Lucifer chose them, while he simply gave his approval.
In a flashback, a conversation between Diavolo, Barbatos, and Lucifer takes place. Diavolo and Barbatos say they are jealous of how Lucifer enjoyed himself in the human world, then Diavolo mentions he's noticed how well MC is getting along with Lucifer and his brothers. Lucifer admits that he trusts MC now, but after he leaves, Diavolo seems worried, and Barbatos suspects that what's about to happen will wound him deeply.
As everyone is walking back to the House of Lamentation, Lucifer asks MC what they and Diavolo were talking about earlier. When they answer, Lucifer states that the reason he chose MC was due to a sudden breeze that scattered the lists, and the list them landed at his feet had MC's name on it. However, he also says that MC is special to him on a personal level. The conversation is interrupted by a call for Lucifer from Leviathan, but when Lucifer picks up, all he hears is a scream before the connection is cut off.
At the House of Lamentation, Lucifer looks for Leviathan in his room, but only finds his D.D.D. laying on the ground. Lucifer then notices that Beelzebub is also missing, so he suggests everyone split up in groups, with Satan and MC together with him. As they search, Lucifer recalls the story about the House of Lamentation. Originally, the house was built in the human world, and a married couple with seven children lived here with their servant.
One day, the oldest son ran into the constable's office with news that their servant murdered his family, then took his own life. The oldest son lived on in the house, eventually dying of old age, despite circumstantial evidence that he could have been the true killer. At some point, the house was given the name "The House of Lamentation."
Once the story is finished, Satan again asks MC to make a pact with him. MC is surprised, but Satan states that he's not asking to make Lucifer angry. He's decided that he won't let what Lucifer does bother him anymore. MC accepts, and now has their fifth pact.
Later on, the three hear screams that sound like Mammon and Asmodeus to Satan. When investigating, he suddenly disappears as well, leaving Lucifer and MC alone. Lucifer suggests they go back to Leviathan's room, and once there, they notice Leviathan's PC is still turned on. Lucifer finds the packaging for the game The Demon House with a description matching what is happening now.
Thinking the game is the cause for the disappearances, Lucifer suggests he and MC complete the game to see what happens. Upon searching for a game guide, it states that in order to complete the game, you must defeat the final boss, whose name is Lucifer. The guide also states that there is a romantic ending where the player and Lucifer fall in love.
MC and Lucifer reconvene in the library, where Lucifer states that the only choice they have is for MC to fall in love with him so they can finish the game. He suggests they start by asking each other questions. When MC asks Lucifer what he thinks of humans, Lucifer suspects the real question is what he thinks of MC. He states that originally, he'd only wanted to make sure MC survived the year, but over time his feelings changed. He asks MC why they made pacts with everyone, and MC finally tells Lucifer they met with Belphegor, which enrages him.
Mammon and the others appear, but when Beelzebub hears about Belphegor being locked in the attic, he and Lucifer argue, leading to Lucifer hurting Beelzebub. Belphegor then appears in the room with them.
Everyone is shocked and confused at Belphegor's appearance. Belphegor confronts Lucifer and things escalate, as Lucifer isn't happy about the situation, and Beelzebub is fed up. In the end, Beelzebub, Belphegor, and MC leave the House of Lamentation.
After leaving, Belphegor laughs at the memory of the look on Lucifer's face, but then asks Beelzebub if it was really okay to leave like that. He answers that he doesn't know, but that they can't go back anymore. He then apologizes for taking MC with them, explaining that he thought it would be dangerous to leave them with Lucifer.
Beelzebub tells MC that the brothers had all gone missing earlier as a practical joke in order to bring Lucifer and MC closer. He then says that sitting and hiding so long has made him hungry, which makes Belphegor nostalgic. Belphegor then comments that he can smell something good, and Beelzebub recognizes the scent of Simeon's BLT devil sandwiches. Sure enough, Simeon shows up, and is surprised at seeing Belphegor. When Belphegor asks him if they can stay at Purgatory Hall, Simeon agrees, but feels like something is going on.
In Purgatory Hall, Beelzebub explains to Simeon, Solomon, and Luke about what's been going on with Belphegor. Solomon and Simeon express disbelief in the entire situation. Belphegor goes on to explain the curse that kept him locked in the attic, which required the power of six of his brothers to break. That why he asked MC to make pacts with everyone.
However, MC explains that they hadn't made a pact with Lucifer, leading everyone to question how the curse was broken. Belphegor claims that he heard a voice, then he found the door was open. Solomon then points out that even if MC had made a pact with Lucifer, it still wouldn't have been enough, as they lack the ability to control the brothers' powers. Simeon then suggests that someone else must have taken Lucifer's place and filled in as the sixth sibling.
Later on, after bribing Luke to let MC, Beelzebub, and Belphegor use his room to sleep in, Belphegor is still relishing in his freedom. Beelzebub tried to press Belphegor for why he was locked in the attic, but Diavolo suddenly appears, and interjects that if Lucifer hadn't locked his brother up, Belphegor might have destroyed the human world.
Both Diavolo and Barbatos enter the room, and explain that Belphegor vigorously opposed the exchange program. He'd attempted to appeal to Lucifer, but Lucifer had supported the program. Diavolo further explains that Belphegor hated humanity and couldn't accept Diavolo's plan for uniting the Devildom, Celestial Realm, and the human world. Belphegor was angry, to the point that he was a threat to the human world, which prompted Lucifer to lock him in the attic for his own protection.
Belphegor becomes angry when Diavolo claims Lucifer was sheltering him, declaring that he was a prisoner in the attic. Diavolo then corrects him, saying Lucifer was indeed protecting Belphegor from him, then has Belphegor arrested for treason. Beelzebub attempts to interfere, but MC stops him. Diavolo warns them both that if they choose to defy him, things will only get worse for Belphegor. He then explains Belphegor will face justice for his actions, and that Lucifer has been placed under house arrest in the House of Lamentation. He then tells MC to stay out of this, claiming it's a demon matter, and as a human exchange student, they have no involvement. Both he and Barbatos then leave, taking Belphegor away.
MC and Beelzebub return to the House of Lamentation with intentions to talk to Lucifer about Belphegor. First, however, goes to Mammon to apologize and ask him for help. Mammon tells MC that Lucifer had locked himself in his room, and to get him out they're going to need as much help as they can get. So, they both go to find Leviathan.
They find Leviathan talking with Henry about how betraying and awful humans are, ignoring MC's and Mammon's presence in his room. Mammon tries to explain that MC's pact with him didn't have anything to do with Belphegor, but Leviathan doesn't believe him. MC makes a TSL reference regarding the friendship between the Lord of Shadow and Henry, leading Leviathan to hug them and call them his true friend.
The trio is then joined by Satan, Asmodeus and Beelzebub, and they all gather in the underground tomb to follow Mammon's plan. He wants MC to touch the grimoire so that Lucifer will leave his room. However, they first need to sneak past Cerberus, who is patrolling the area.
When MC touches the grimoire, they see a flashback of when Lucifer fell into the Devildom with a dying Lilith after the Great Celestial War. Diavolo appears before him, and at Lucifer's request, promises to save Lilith. However, in return for the great risk of interfering with the Celestial Realm's judgment, Lucifer would have to pledge his loyalty to Diavolo. To this, Lucifer agrees.
When the flashback ends, MC tries to pick up the grimoire, but can't because of the ivy covering it. As Cerberus approaches, Lucifer appears and commands him to sit. MC can either hug or hit Lucifer, and both responses surprise him.
MC gathers everyone back into the mansion to talk about Belphegor. Lucifer reveals that he had locked Belphegor away for his own protection, because he was openly against the human race and put Diavolo's exchange program in jeopardy. Belphegor's reason for hating humans stems back to Lilith's death, as he believes that humanity was responsible.
Meanwhile, back in the Purgatory Hall, Luke is worried about MC and Beelzebub, while Simeon and Solomon try to calm him down. Solomon wonders why Lucifer is loyal to Diavolo, and Simeon comments that Diavolo and Lucifer seem like close friends rater than master and servant, or at least Diavolo sees Lucifer like that.
In a flashback of Simeon visiting the Devildom for the first time after Lucifer's rebellion, he finds Diavolo being extremely friendly with Lucifer, to the point Lucifer had to stop him from embarrassing him any further. Solomon's and Simeon's conversation is interrupted by Luke yelling about his burnt cookies.
In one last flashback, Belphegor is talking to himself in the attic when Lucifer appears. He asks if Belphegor has calmed down yet, reminding him that he was meant to use the time in the attic to rethink what he'd said earlier. Belphegor responds that he'll be stuck here forever, because he'll never change his mind.
Lucifer tells him they're chosen the second student from the human word, and that they are an average, non-magical human. Belphegor threatens to tear them to shreds, ruining both the exchange program and Diavolo's reputation. Lucifer tells him that won't happen, because the door to the room can only be seen by demons, and the stairs are cursed so that no demon but Lucifer can climb them.
After Lucifer's explanation as to why Belphegor was locked in the attic, MC asks why he hates humanity in the first place. The brothers explain that, as an angel, Belphegor loved humans and often visited the Human World in secret. His visits led to their sister and youngest sibling — Lilith — also being interested in humanity, and eventually to her falling in love with a human. Unfortunately, the man was stricken with an incurable illness, and in an attempt to save him, Lilith gave him forbidden food from the Celestial Realm.
Because altering the lifespan of a human is forbidden, when caught, she was sentenced to be wiped from existence, which of course Lucifer and his brothers refused to accept. Their rebellion turned into what was afterwards called the Great Celestial War. It was a war the brothers lost, and fell into Devildom, becoming demons.
Belphegor blamed the man Lilith had fallen in love with, and argued that she wouldn't have died if neither he nor humanity as whole had never existed, so he began hating humans. However, Lucifer also reveals that Lilith did not die at the end of the war, but was instead saved by Diavolo and reborn as a human, which is why Lucifer swore his loyalty to him.
After hearing all of this, MC and the brothers decide to pay Lord Diavolo a visit. They ask Diavolo to release Belphegor, to which Diavolo eventually agrees, but only under the condition that MC travels back into the past and ascertain exactly who it was that freed him from the attic.
With the help of Barbatos, MC returns to the time when the brothers were pretending to disappear. After being spotted by them, they explain that their plan was to get Lucifer and MC alone together to make up. The brothers urge MC to go back to Lucifer and patch things up, so MC leaves. They arrive outside Leviathan's room to hear Lucifer complaining about how ridiculous the game is, then nearly run into both him and their past self.
To avoid being seen by their past self, MC hides in the hidden replica of Lilith's bedroom. They start seeing disconnected events of the past, including an argument between Lucifer and Belphegor about the exchange program. MC heads to the attic to find the door to Belphegor's room missing, but after touching the wall where it should be, the door magically opens.
They enter the room, and Belphegor overwhelms MC with his appreciation upon realizing that he is free. However, suddenly he turns into his demon form, and mocks MC for falling into his trap. He then attacks them, intent on ending the exchange program by killing MC.
MC faints from the pain, and they hear the voice of Lilith in a dream-like world. Lilith explains she no longer has a physical form, but after her death as a human, she recalled her memories of her past life. Since then, she'd been watching over her brothers as a soul. Lilith then lends MC her powers so that they can save her brothers.
In the timeline MC left, the brothers anxiously await MC's return, minus Lucifer and Beelzebub, who visit an imprisoned Belphegor only to find him sleeping. Lucifer apologizes to Beelzebub for lying to him about Belphegor being in the Human World, and Beelzebub tells Lucifer he can make up for it by trusting his brothers more.
Back in the past, MC wakes up completely unharmed. They hear an argument downstairs, and head to the source to find a duplicate of themself dying in Mammon's arms. The brothers are panicking, horrified at the idea of MC dying, when they spot the future MC standing there. After a moment of confusion, the MC in Mammon's arms disappears. Belphegor begins to attack MC again, but stops when MC tells him about what really happened with Lilith.
Lucifer asks where MC heard that story from, and Diavolo enters the scene to reveal that MC is a distant descendant of Lilith's. He asks MC if they ever had visions of Lilith's memories, and MC recalls the memory of Lucifer pledging his loyalty to Diavolo. Diavolo then postulates that some of Lilith's angelic powers and memories remained even after being reborn a human, and both had passed on through her descendants.
The brothers are overjoyed both that MC is alive and well, and to learn that their sister lived a happy life that resulted in MC being here with them now. Belphegor apologizes, and finally admits the truth; he blamed himself for Lilith's death, but tried to escape his feelings of guilt by blaming humanity instead. Lucifer responds that Lilith's death wasn't his fault, and that he should've told him that sooner.
Some time afterwards, the brothers — including Belphegor — are fawning over MC. MC asks Barbatos about their disappearing double, and he tells them another power of his: he can choose from any number of potential realities and make his choice the sole reality. Because the reality he chose was one where MC was never harmed, the other MC disappeared, having no longer ever existed.
In a flashback, Lucifer is buried in paperwork for choosing the second human exchange student. Diavolo suggests choosing a human completely different from Solomon, but when Lucifer decides to take a break and open a window, a gust of wind sends the paperwork flying everywhere. The paper that landed at his feet has MC's name on it, and Lucifer decides they will be the second human student. Diavolo states that nothing is a coincidence in this world, and agrees with Lucifer's decision.
The brothers are having breakfast as usual, but when Belphegor enters, things get awkward. Leviathan announces that he's going to grab his food in the cafeteria. Beelzebub, Satan, Mammon and Asmodeus come along. Asmodeus questions MC whether they are coming along too, to which they can either agree, or say that they'll wait for Belphegor. Lucifer then enters to announce Diavolo's birthday party, and everyone heads to RAD.
Belphegor notices his brothers' wariness of him, as does MC, so Simeon suggests MC "serve as a bridge" for the brothers. After school, MC goes to the planetarium with Belphegor, and asks them what they were planning on giving Diavolo for his birthday, but they're interrupted by a loud noise coming from the music room.
They catch Mammon rummaging through the room, and Belphegor accuses him of stealing. Mammon retorts that he wants to give someone a present. Belphegor asks if the present is for Diavolo's birthday, and Mammon seems to suddenly remember that's coming up soon, but agrees that the present is for Diavolo. Belphegor changes the topic to getting money for Diavolo's present. He suggests working in Hell's Kitchen, which the three decide to do.
Afterwards, Leviathan meets up with MC, and says that Belphegor wants to play games with him. He worries that it would be awkward, so he tells MC to give Belphegor the message that he's busy waiting to accept a package from Akuzon. MC leaves for the twins' room and gives the message, but Leviathan shows up to say the package had been delivered, so he brought some games with him for all three of them to play. Belphegor falls asleep in the middle of gaming, to which Leviathan seems surprised and slightly disappointed, but then comments that he shouldn't have worried about things being awkward.
Later, MC and Belphegor are playing card games, with Belphegor repeatedly losing. Lucifer then enters, and wants to talk with Satan about Diavolo's birthday. Satan agrees, and the two leave. Belphegor notes that Satan was acting strangely agreeable with Lucifer, and asks MC if they know anything. MC tells him about the forbidden book incident, and how Satan and Lucifer's relationship changed.
After the story, Belphegor says wishes he'd been there. Satan returns and overhears them, then comments on how he still loves to see Lucifer suffer. Belphegor then suggests forming "The Formerly Anti-Lucifer League" with the goal to make Lucifer's life as hard as possible. The three adjourn to the library to discuss the group's first prank: putting hot sauce in Lucifer's prized vintage Demonus.
Said Demonus is kept in Lucifer's study, which is behind a secret door in the library. They assume a secret code or phrase is needed to lift the enchantment and open the door, so start trying taunting phrases to get the door open. Unfortunately, they are caught by Lucifer, who tells them to come with him for a stern talking-to.
MC and Belphegor are out shopping for Diavolo's birthday present, when Solomon appears, and tells Belphegor he'd like a pact with him, He notices that Belphegor glances in MC's direction, then declines his offer of a pact. He and MC then head back to the House of Lamentation, where Asmodeus comes along and drags them both to his room. He asks MC what sort of outfit they like, then reveals that the outfit is for MC, but Belphegor then pulls MC out of the room.
Later, MC, Leviathan, and Mammon are playing a video game in MC's room, but Belphegor interrupts them after a fight with Beelzebub. He tells them that it was because Beelzebub was feeling guilty due to not knowing Belphegor was being held prisoner. Belphegor asks MC if he can sleep in their room, but Mammon aggressively declines, and offers to help Belphegor and Beelzebub to make up.
When MC and Mammon search for Beelzebub, they find him in the kitchen cooking soup for Belphegor. The three take the soup back toward MC's room, and Beelzebub worries whether or not Belphegor would forgive him. Leviathan and Belphegor come out of MC's room, and Belphegor, tired of Beelzebub's behavior, slaps him, and says firmly that what happened wasn't Beelzebub's fault. The two are then able to make up.
After a day of school, Lucifer invites MC to go shopping with him for Diavolo's present, and then the two have dinner at Ristorante Six. Lucifer raises the topic of MC helping Belphegor and his brothers patch things up, and thanks MC for helping them. Then then return to the House of Lamentation to find Belphegor, and Lucifer invites him as well as MC to come with him and provide an opinion.
He leads them to Lilith's room from the Celestial Realm, and confesses that he created the room to never forget Lilith, but the secret of Lilith's reincarnation had been too much too bear, so he'd unloaded it all here. He says that he doesn't need the room anymore, but wants Belphegor to use it if he needs it. Belphegor says that he also doesn't need the room, but thanks Lucifer for being able to make the decision, and the two make up.
At the Demon Lord's Castle begins, Diavolo's party begins, but he reveals in a speech that the party is meant for MC too. The brothers all give MC their gifts, but Belphegor is nowhere to be seen. MC finds him in the garden, where admits he wasn't sure what to give MC, so he decided to give himself. He makes a pact with MC, and then Asmodeus, Beelzebub, and Mammon find them, and urge them to go back to the party.
In a flashback before the party, the brothers are in Lucifer's private study, where he announces his idea of making Diavolo's birthday party also be a welcome party for MC. Asmodeus decides to buy a present for MC, so the others decide to do the same. Belphegor raises the idea that he should give MC himself by making a pact with them. The other brothers each try to subtly ask MC what they would want as a gift.
After the birthday/welcome party is over, Beelzebub and Satan are playing chess in the music room with MC and Belphegor. Lucifer then enters, and tells Belphegor that he has to make up for all his missed classes. He gives Belphegor all of his assignments, and tells Beelzebub and Satan not to help him.
Later, Belphegor is studying in the twins' room with MC helping, when one by one Mammon, Asmodeus, Satan, Beelzebub, and Leviathan each enter the room. They all try to help Belphegor in their own ways, but are mostly just distracting. Belphegor finally snaps, and takes MC with him to his attic room. He thought he could now focus on his schoolwork, but instead falls asleep on MC's shoulder.
The brothers are once again having breakfast, and as Beelzebub eats Leviathan's meal again, everything in the Devildom seems back to normal. Belphegor enters as the room, and Mammon comments that he woke up even later than Leviathan. Lucifer then also enters the room, and asks MC to join him tomorrow for a meeting with Diavolo discussing the end of their stay as an exchange student. The room is filled with silence, as all of the brothers are upset.
Breakfast ends, and everyone is getting ready to head to RAD. Lucifer requests MC stay behind, and tells them his brothers are sad that MC's leaving, so he wants MC to spend as much time with them as they can. Once classes are over, Mammon invites MC to hang out, but Leviathan interrupts, demanding Mammon give his money back. Mammon makes a break for it with MC, but Leviathan is close behind.
Still being chased, MC can either suggest hiding in Mammon's room or Leviathan's room. If MC suggests Mammon's room, they'll hide in the trunk of his car. If MC chooses Leviathan's room, they hide in Leviathan's bathtub he uses as a bed. Leviathan enters, then tells Henry that he's sad MC is leaving next week. He eventually leaves the room, and MC and Mammon leave as well.
The two make it out of the House of Lamentation and get some distance between themselves and Leviathan. Mammon laughs about the look Leviathan had on his face as they escaped, then questions MC about staying in the Devildom. However, Leviathan has caught up to them, so Mammon runs away. Leviathan, tired of chasing him, and admits that he too, wants MC to stay in the Devildom.
The next day, the scheduled meeting takes place in the Student Council Room. Diavolo states that Lucifer seemed distraught over MC going back to the Human World, and that he's also sad about MC leaving. Once school is over, MC is spotted by Asmodeus, who invites them to hang out. The two go to Hell's Kitchen, where Asmodeus challenges MC to a drinking contest.
The contest involves drinking Demonus — a common alcoholic Devildom beverage — which turns out to have no intoxicating effect on humans. Because of this, MC wins the drinking contest, which leads to a drunk Asmodeus hugging MC with tears in his eyes as he asks them to stay in the Devildom. Satan finds them like this, and carries Asmodeus back to the House of Lamentation.
He puts Asmodeus to bed and returns to his room, where MC was waiting. He has something to ask MC, and starts talking about a book of old folktales he recently acquired from the human world. In one story, a king is given aid in winning a war by a beast with magical powers. The king then kills the beast, who turns into a monster and curses the entire country. To end the curse, the king offers his newborn daughter as sacrifice. Twenty years later, the daughter is seen still alive, and people try to kill her out of fear. The monster appears and saves her, giving up his own life.
Satan asks what MC thinks the beast felt in its dying moments, and then wonders in confusion what it is he's feeling for MC now. He says that he knows MC returning to the Human World doesn't mean they'll never meet again, but the thought of them not being around still makes him sad.
MC is at RAD chatting with Simeon, Luke, and Solomon about leaving the Devildom. Solomon suggests they should all meet up again someday, and everyone agrees. After school at the House of Lamentation, MC finds Beelzebub searching for Belphegor, and helps look for him.
Eventually, MC and Beelzebub find Belphegor sleeping in the attic room. Beelzebub is relieved to find him, then thanks MC for bringing their family together. Belphegor then wakes up, and Beelzebub admits to Belphegor his worries about him running away. Belphegor tells him not to worry, and Beelzebub heads for the kitchen.
After Beelzebub's gone, Belphegor suggests that he, Beelzebub, and MC live together, but then admits what he's asking is selfish, because MC has a life in the human world to return to. Beelzebub then returns with a mountain of snacks, followed by Mammon, Leviathan, Asmodeus and Satan. A going-away party begins, but after awhile MC leave to find the door to Lucifer's secret study is open, and music plays within.
MC goes inside to find Lucifer listening to the cursed vinyl edition of The Tale of the Seven Lords soundtrack. Lucifer notes that he chose MC as the exchange student in this room, and that while there were times he thought he'd made a mistake, he's now certain he made the right choice. He asks MC if they finished everything they set out to do in the Devildom, and MC answers that they haven't made a pact with him yet. Lucifer then turns into his demon form to intimidate MC, and asks if they still want a pact with him. Regardless of MC's answer, Lucifer still makes the pact.
On the final day, Diavolo, Barbatos, the seven brothers, and the exchange students are is gathered in the Student Council Room, where said exchange students will be sent back to their own worlds. Simeon, Luke, and Solomon leave first, after saying their goodbyes. Diavolo gives his farewell to MC, followed by each of the brothers, before MC returns to the Human World. MC then gets a message from Solomon informing them they can still use their D.D.D. in the human world.
Some time later, Barbatos serves Diavolo tea that he procured from the human world, which makes Diavolo think of MC. Barbatos notes that it has been quite a while since MC left, yet everyone is still in low spirits. He questions whether Diavolo is unhappy. Diavolo admits he might be, then asks Barbatos if he's sad his baking partner Luke is gone. Barbatos answers that he is.
At the House of Lamentation, Leviathan and Mammon are arguing over money Mammon owes, to which Lucifer threatens Mammon with hanging him upside down. Satan complains that he was hoping for someplace quiet to read his book, then Asmodeus starts complaining that Beelzebub ate his special sweet he wanted to post about on Devilgram. He wishes MC were there, and Leviathan agrees that they'd find a way to fix everyone's conflicts.
Belphegor then enters, and comments that the room feels somber before asking if anyone had seen his D.D.D. He says today is the day MC calls him, which fills the others with shock and jealousy. Everyone then hears Belphegor's D.D.D. ringing.