Housewife Natsuki was happily married, raising her stepson and enjoying a peaceful life with her husband. When her husband went on a business trip, leaving her slightly lonely, she began masturbating one day—only to be caught in the act by her son's friend who had come over to visit. From that moment on, her life changed completely. Surrounded by her son's friends, Natsuki's body is toyed with as she wavers between pleasure and guilt. Her daily life as a devoted wife begins to crumble, forcing her onto a new, unexpected path.