Mikawaya has been in love with Erina for a long time. One day, Mikawaya's desire explodes when he witnesses Rina masturbating. However, Erina, who has a strong libido, accepts Mikawaya, who approaches her roughly. And from that day on, an obscene life with Mikawaya began almost every day. However, such a life can't last long, and the son who witnessed the two obscene acts...
