In'youchuu ~Chronicles of Demon Exorcism at the Violation Academy~

The starts at the office of the demon hunter company, the "Black Cat Brigade". A phone call informs them of a case regarding a haunted school, the case sounds simple and since Mikoto is afraid of ghosts and Yamato is too much of a trouble maker, Takeru decides to take care of the case by herself. - One week passes and Takeru has interrupted all communications, which is very unlike her, so Mikoto and Takeru decide to go looking for her at the school. - Once there they find a pretty normal situation but no trace of Takeru, so they decide to act as students, with permission from the principal, to look for her without raising suspicions. - They also meet with Sui, Yamato's childhood friend who clearly has feelings for him, who says she met Takeru right before she disappeared. - It quickly becomes clear that something strange is going on in this seemingly peaceful and respectful private institute in the middle of the mountains....​