Beautiful girl Kokoro lives in a single-parent household with her mother. One day, her mother Mary, who works at a snack bar, invites over her new partner, Kitashita, to their home. In front of Kokoro, Kitashita reveals his relationship with Mary and immediately begins sexually enticing the young girl, gradually asserting control over her. He slowly caresses and arouses Kokoro, implanting intense pleasure within her. Eventually, he takes her virginity. But it doesn't end there—using her mother's debt as leverage, Kitashita sells Kokoro to the loan sharks. One after another, despicable men rape her, and Kokoro gradually awakens to her masochistic desires, embracing a new, darker lust within herself.