"I came back to take revenge on you." Obscene sounds echoing through an empty staff room. Fingers being pushed skilfully into a place where no one else has touched…" Minami, a target of bullying during his junior high school days, with his one and only friend Nozumu Kai. However, an event causes Minami to hurt his friend and a rift between the two friends is created, causing them to lose contact.
Ten years later, the two are reunited as teachers in the school of their past, and just when the distance between them begins to close, bullying reminiscent of their junior high school days begin to arise around Minami once again.. 「オレはお前に復讐するために戻ってきたんだよ」誰も触れたことのないソコに押し込まれた指が巧みにナカをかき乱し、誰もいない職員室に響く淫猥な水音…。――中学時代いじめられていた南。そんな南の唯一の友達・甲斐。だがある出来事をきっかけに、甲斐を傷付け疎遠になってしまう。それから十数年後、2人は教師となり思い出の校舎で再会。再び距離を縮めていたある日、中学時代を思い出させるようないじめが南の周囲で起き始め…。