House of Lamentation
The House of Lamentation is a large mansion located in the Devildom, and is where the seven demon brothers Lucifer, Mammon, Leviathan, Satan, Asmodeus, Beelzebub, and Belphegor live. Beginning after their acceptance into the student exchange program, MC also spent time living with them.
In Lesson 1-7, Mammon explained that the House of Lamentation is the RAD dorm reserved for student council members.
The house's architecture looks to be Gothic Revival, and there are seven headstones in the front yard. There's also at least one tree within the house, for there's one in the MC's room and one seen in the hallway. It's unknown if these are both the same tree.
- Asmodeus's Bathroom
- Common Room
- Communal Bathroom
- In Lesson 42-C, there's an established bathroom order which the brothers decided on a rock, paper, scissors competition. With the exception of Asmodeus, everyone uses this bathroom to take showers/baths.
- Dining Room
- Entrance Hall
- Laundry Room
- Living Room
- It's connected to the Entrance Hall, for the mirror can be seen in the entryway.
- Lucifer's Study
- Can be accessed from a secret passage in the library.
- Music Room
- In the Devilgram Living the Dream, the music room is connected to the dining hall, for the brothers could hear Levi singing in there.
- Underground Tomb
- As seen in Lesson 40-20, the tomb has an emergency escape route that leads to the far reaches of the Devildom.
- Lucifer's room
- Mammon's room
- In the Devilgram Proud Brothers, it's stated that Mammon's bedroom is next to Satan's.
- Leviathan's room
- This room was not always located where it is now, as Leviathan mentioned having moved rooms in Lesson 7-17.
- Satan's room
- Asmodeus's room
- Beelzebub's and Belphegor's room
- There is a secret passage in this room's closet that leads to the Underground Tomb.
- MC's room
- Their room is located next to the kitchen, as evidenced in Lesson 5-2 when Beelzebub destroyed a kitchen wall shared by MC's bedroom.
- According to the chat Changing Rooms, MC's room is separate and at some distance from everyone else's rooms.
- Their room has its own bathroom, as alluded to in Lesson 4 — when Mammon left his toothbrush there — and in the chat Bath Time with Asmo 1.
- The room has a desk within it, and one of the drawers of which possesses a lock. Lucifer suggested MC keep their valuables within it in Lesson 2-4.
- Lilith's room
The House of Lamentation was originally built in the Human World on the outskirts of a village. The people who previously lived there were a married couple with their seven children, and their servant.
One day, a terrible tragedy struck inside the house. Every family member was brutally murdered in a different way, in a different room, and the servant had hung himself in his own room. The only survivor was the eldest son, who claimed the servant committed the crimes. The authorities deemed the case closed, but rumors started spreading that the eldest son was on bad terms with his family. It was then believed that the servant tried to stop him but was killed and framed to be the scapegoat for the murders. The son continued living in the house until he died of old age.
Afterward, there were figures seen in the windows, and screaming and arguing could be heard despite being vacant. Because of the dark history, the mansion became known as the "House of Lamentation."
Eventually, the mansion was transported to the Devildom and became a dorm for the demon brothers.