Kuraishi Kanna, once a beloved honor student, transforms into a rebellious "kogal" delinquent following her parents' divorce. Her homeroom teacher, Kisaragi Ren, who secretly idolized her former diligent self, becomes consumed by rage over her new impudent behavior. This frustration culminates in a dark power struggle as Ren resorts to coercive and predatory means to punish Kanna and force her submission.