Hiinatsuki Dormitory

Hiinatsuki Dormitory (雛月寮) is the place where Rokuro Enmado stayed when he was young and where young exorcist cadets stay for training.

History
Two years prior current storyline, the Hiinatsuki Dormitory is where the 18 Exorcist Cadets were staying until the tragedy of Hiinatsuki Dormitory happened. Supposedly, Hiinatsuki Dormitory was attacked by dozens of impurities that appeared from Magano, and the 18 Exorcist Cadets that were there died.

Tragedy
Rokuro Enmado, who shows talent for exorcism was envied by the other exorcist cadets. Yuto Ijika tells the other exorcist cadets that there is a way to improve themselves by using a sort of ritual. It was his experiment in using Impurities to improve the human body. All 18 cadets who fell and became Impurities were exorcised by Rokuro but he didn't escape Yuuto's experiment and soon his arm became that of an Impurity's arm.

Trivia

 * Rokuro is the official sole survivor of that incident.