Arihiko Tairaku, a 24-year-old high school teacher, works at an institution infamous for its violent, delinquent student body. His days revolve around managing chaotic classrooms where absenteeism runs high, leaving him to defuse sporadic acts of aggression. Though aware his efforts may prove futile, he clings to a rigid sense of duty, routinely enduring physical harm while intervening in student conflicts. His routine fractures after discovering Aya Shirakaba, a teenage girl smoking alone at night. His reprimand sparks her obsessive infatuation, prompting her influential yakuza father to coerce him into becoming her guardian. Tasked with safeguarding Aya’s safety and chastity until graduation—under threat of death for failure—Tairaku finds himself trapped. Aya invades his home unannounced, forcing him to navigate the ethical minefield of their cohabitation while hiding her presence from colleagues to protect his career. Secretly drawn to fellow teacher Yayoi Satsuki, whose company he occasionally shares, Tairaku’s hopes for romance fray as Aya’s relentless flirtations and seductive ploys escalate tensions. He struggles to shield her from predatory peers, opportunistic criminals, and his own vulnerabilities, including alcohol-fueled lapses in judgment that risk his precarious balance. Plagued by relentless misfortune, Tairaku stumbles into humiliating or perilous scenarios, yet persists through a combination of stubborn self-preservation and quiet moral resolve. The narrative traps him in a web of conflicting loyalties—duty to Aya, terror of yakuza retribution, and yearning for personal fulfillment—leaving these tensions unresolved in existing accounts.