Towa, a shut-in, is subjected to daily sexual abuse by her stepbrother. "I went shopping for you, Towa-chan," her stepbrother says with a servile smile, offering kindness that always comes with an expectation of reciprocation. "Since I did you a favor, please make my cock feel good..." He rubs his hardened crotch against Towa, becoming aroused. He intends to stay in the room until he ejaculates, pestering her relentlessly. Overwhelmed by everything, Towa gives in to her stepbrother's demands. However, his sexual desire gradually spirals out of control...