Shizuka's son, Shinichi, has an uncontrollable sexual desire and is always masturbating. His room was littered with AVs and masturbators, and he indulged in masturbation whenever he had time. Shizuka's neighbor ``Kohananon'' also has a strong sexual desire, and because of her strong sexual desire, she is dumped by a sex friend. When he tried to have phone sex, he was refused, and his sexual desire was so strong that he continued to masturbate.