Worried about her son who has been drained and listless from work-related stress, mother Emi tries to comfort him. One night, while Emi and her husband are having sex, her son secretly watches from his room, visibly aroused. Emi notices him peeking but pretends not to see. The next day, she visits her son's room and gently brings up the incident from the night before. Finally, she asks, "You were hard, weren't you?" and reaches down to touch his crotch. Wanting to cheer him up, Emi tells him, "You can do whatever you want with Mom's body," as she begins undressing. Hesitant at first, her son grows increasingly excited and, with her guidance, they slowly give in to their desires and make love.