Ayaka's husband is away on business all year round, so Ayaka been living alone with her son. Because of this, her son Shinsuke tends to depend on Ayaka, and she worries about his future... One day, she sees Shinsuke indulging in masturbation. As a mother, Ayaka tries to teach him about sex, but Shinsuke, who has begun to think of his mother as a woman, can't help but push her down. She laments that she has done something irreparable, but since that day, Shinsuke has been trying to make love to Ayaka at every opportunity...