Married woman Yuki is faithful, pure, and values chastity. While cherishing her relationship with her husband, she is placed in an extremely difficult position—offering her body before her husband's superior to secure his promotion. To fulfill the promise of giving her husband favor in the eyes of his boss, she suppresses her own will. Forced to serve the men around her and even participate in sex with her husband on demand, she gradually crosses her limits of endurance. Burdened with shame and confusion, her body slowly transforms into that of a sexual slave.