House of Lamentation

Located in the Devildom, The House of Lamentation is a huge mansion where the seven demon brothers Lucifer, Mammon, Leviathan, Satan, Asmodeus, Beelzebub, and Belphegor live. After the beginning of the Exchange Program, MC lives with them. They all have individual rooms, except for Beelzebub and Belphegor who share a room.

Related links
House of Lamentation Memory Box House of Lamentation Gallery

Background
The mansion 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 oldest son, who claimed the servant committed the crimes. The authorities deemed the case closed, but rumors started spreading that the oldest 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 in Devildom and became a dorm for the brothers.

Trivia

 * Lilith's room was from the Celestial Realm and likely added by Lucifer after he and the brothers moved in, for Beelzebub had no knowledge of its existence.
 * The attic was considered Lucifer's private sanctuary where he kept things from the Celestial Realm, perhaps even Lilith's things. Lucifer went to great lengths to keep his brothers away from it, including casting a spell that prevented them from entering it, but it doesn't work on humans and angels.
 * There are seven headstones in the front yard.
 * The architecture looks to be a Gothic Revival.
 * MC's room is stated to be on the other side of the kitchen, as confirmed in Lesson 5-2 when Beelzebub destroyed a section of the kitchen wall which was also part of MC's bedroom.
 * The Mausoleum is likely a part of the mansion for there was an effigy of Lilith with her holding the brothers' grimoire, and Cerberus was patrolling the area later on.