Ouma no Shoku ~Sei ni Tsukaeshi Yami no Guuzou~

The protagonists are members of the theology club at St. Rising Truth Academy. Besides of being a place of study, this university prep school puts a lot of effort into the sacred teachings and volunteering. The female teachers on campus have become unhinged, which quickly became a problem. Right when the school is about to take measures to solve the issue... the female teachers disappear without a trace. Two members of the "Newspaper Club," that is on the brink of dissolution, have their eyes on the scoop and move out to investigate the situation. These two are the protagonist, Mibu Mutsuki, and his twin sister Hazuki. "If we can get our hands on that scoop, then we'll get so many members!" Dragging Hazuki - who's brimming with motivation - with him, they head out to investigate the case. While they investigate the surroundings of the disappeared female teachers, what's unsolved soon unravels. But the tentacles of evil are already creeping up on them both.