The Black Cat Demon-Hunting Agency gets a call about demonic happenings at Shunju Academy, so they send Takeru, their most competent member, to investigate. However, when Takeru neither returns nor calls to check in, Mikoto and Yamato head out to find her. Upon arriving at the school, not only is Takeru not there, the deputy principal tells them she already conducted her investigation and left. There’s still demonic auras afoot, so Mikoto and Yamato must further explore the academy, search for demons, and find out what truly happened to Takeru...