The series follows school advisor Rena Hayakawa, who discovers her own sister, Mina, being fucked by a male teacher on campus. Attempting to intervene, Rena finds herself caught in a web of blackmail. The teacher and his depraved colleagues use the compromising situation to turn Rena into their personal fucktoy. Across the series, Rena is relentlessly subjected to a series of humiliating and degrading sexual acts. She's forced into group sex scenarios, her orifices stretched and filled by multiple cocks at once, and made to perform fellatio and cunnilingus on her blackmailers. Each episode escalates the depravity, exploring her forced submission as she is anally and vaginally dominated, her body used as a cumdumpster by the lust-crazed men who now control her life.