Yukie Kitazawa, a Japanese housewife, endures a strained marriage after her husband develops impotence stemming from suppressed attraction to their younger adopted daughter, Tomoko. This leaves Yukie deprived of intimacy. Her life fractures when she causes a car accident involving Taketo Nogawa, the son of a wealthy, corrupt businessman. Unable to pay the damages, Yukie agrees to compensate Taketo sexually through a contract facilitated by Yumi Okamoto, her father's secretary. This arrangement inadvertently entraps her two adopted daughters, Rumi and Tomoko, in subsequent exploitation.

Taketo, impulsive and frustrated, exploits the contract for ongoing sexual access to Yukie. Concurrently, Taketo's father uses the same agreement to blackmail first Rumi, then Tomoko, into compliance, widening the family's victimization. Yukie experiences conflict; despite the exploitation, she welcomes Taketo's sexual attention due to the prolonged deprivation in her marriage.

Later, Yukie's husband returns but struggles with uncontrollable urges towards Tomoko, further destabilizing the household. Taketo positions himself as attempting to maintain the family's unity amidst the turmoil, though his motives remain unclear. Yukie remains central throughout these escalating conflicts, her initial decision triggering a cascade of manipulation and abuse engulfing her daughters.

She navigates complex emotional terrain, balancing her maternal role against her own needs and vulnerabilities. The narrative emphasizes her entrapment within a feud between Taketo and his father, both exploiting the Kitazawa women to assert dominance over each other.