The Takakura family was a happy family, though they could not afford to have parents and one son. As the son grew up, the couple gradually became sexless. However, Rina's sexual desires only grew stronger, and she satisfied them by masturbating every night. One day, when her son was about to graduate from college, she discovered that her husband had been cheating on her, and the relationship between the couple suddenly became cold. Rina's only source of Kokoro support was her son.