Professor Yoshihiko Ohse is a faculty member at Aoi College whose initial eccentricity masks extreme psychopathic tendencies. He orchestrates a campus hostage crisis using remotely detonated bombs, threatening students and staff to enforce compliance. His actions stem from deep disillusionment with the education system, which he condemns for imparting useless knowledge without practical application or purpose. This fuels his creation of brutal "lessons" centered on terror and degradation.

Past failures and professional setbacks contribute to his descent into depravity, solidifying his belief that conventional education breeds complacency. He justifies employing torture, sexual violence, and public humiliation as necessary tools to "awaken" his hostages. Ohse exhibits a calculated, manipulative personality, wielding psychological tactics like isolation, exploiting fears, and framing his atrocities as essential enlightenment.

During the siege, he forces students, primarily 19-year-olds, into acts of extreme violence and degradation, including sexual assault and public nudity, broadcasting some events externally. He rationalizes this as exposing societal hypocrisy and the fragility of institutional authority. His methods rely on remote-controlled explosives and improvised weapons, highlighting technical ingenuity and premeditation.

Physically, Ohse has brown hair and green eyes. He often maintains a calm demeanor punctuated by sudden outbursts of sadistic enthusiasm. He shows no remorse, viewing his victims as participants in an immersive critique of societal norms. His character arc concludes within the hostage narrative without redemption or moral ambiguity, remaining a terrorist driven by nihilistic ideology.