Ritsuko Kawai, a stepmother who remarried and now lives with her husband and his son Yoshio, struggles with a sexless marriage and unfulfilled desires. Sensing her inner turmoil, Yoshio begins to seduce her, gradually turning her into his sex slave. Obedient to his commands, Ritsuko plunges into lewd and pleasurable affairs, slowly losing herself in the process. Eventually, Yoshio involves his classmate, and during her husband's business trip, the boys' desires spiral out of control. A story where lust and emotion intertwine, revealing how this twisted relationship evolves among the three.