Azusa's son, Koji, is a sex monster who thinks about nothing but ejaculating whenever he has free time. She was at her wits' end with her son, who would see his own mother as a sexual object when he lost all reason. But then she remembered her friend, the slut Mary of the Tachibana family, and consulted her about her son. The sex monster battle between Koji, who has an endless amount of sexual desire, and Mary, who offers to handle it, is about to begin.
