Six months after reconciling with her husband, Iroha attempts to rekindle their intimacy. During their first sexual encounter in half a year, her husband suffers erectile dysfunction and only manages to climax using a vibrator. Unbeknownst to them, their son secretly watches the entire scene from his hiding spot. Afterward, he becomes obsessed with the image of his mother and begins masturbating frequently. One day, Iroha walks into her son's room and catches him in the act. As she apologizes in shock, he tells her, "You watched me jerk off, so now you have to let me see you too," and forcefully approaches her. He strips her clothes off and penetrates her with his erect cock. That night, their forbidden relationship takes a shocking new turn.