Yuu's only son thinks that the reason he's not popular is because he resembles his father. Feeling sorry for him and being overprotective, Yuu helps him masturbate, and so a forbidden relationship between Yuu and his son begins. Her excessive sexual demands eventually lead to intercourse... and even though she knows it's not allowed, she takes his virginity. And before she knows it, Yuu herself is becoming deeply addicted to her son's cock...