New teacher Rena visits a student from her class, but the student suddenly drags her into his room, forces her to drink tea laced with a sedative, and pins her down. Just as the assault is about to begin, the boy's delinquent father arrives and violently intervenes, gang-raping Rena without mercy. That night, the father is summoned by loan sharks he owes money to, who propose using Rena's body as collateral. Rena accepts the offer, gradually submitting to acts she once refused—creampies, facials, and more—transforming into an insatiable, depraved woman.