Rin lives alone with her son Kazuya, while her husband is away on a long business trip. One day, Kazuya's classmate Ashida comes to apologize for bullying Kazuya... Rin sympathizes with Ashida's situation, as he sincerely apologizes, and begins to look after him in every way possible. However, Ashida's Kokoro is to repay her Kokoro with evil... As soon as they are alone, he forcibly makes love to her. Although it was unavoidable, Rin is troubled by her illicit affair with her son's classmate. However, she cannot suppress the throbbing of her body from the pleasure of a man's penis, which she has not experienced in a long time...