After causing a fatal car accident that killed her senior, Kozue, Yuki is forced to confront the victim's father, Uekawa, alongside her own. Uekawa suddenly demands an extreme compensation: Yuki must become the adopted daughter of the Uekawa family in place of his deceased daughter. Though she refuses, Uekawa pressures her by offering to clear her father's massive debt, coercing her into the adoption against her will. As the new daughter of the Uekawa household, Yuki is subjected to strict discipline. Using her mistakes as excuses, Uekawa gradually tightens his control, escalating into repeated acts of physical and sexual abuse, turning her into his personal sex slave and cumdump.