Hidemi is fed up with her husband, who is selfish and only has rough sex. Yuki (her son), who has been spying on the couple's lovemaking, feels sympathy for his mother due to his father's self-righteous behavior and begins to develop feelings for her. One day, Hidemi witnesses Yuki masturbating with her panties. Things continue as usual as if nothing had happened, and when Yuki goes out, Hidemi comforts herself as if to dispel her anguished feelings. Yuki returns home to get something he forgot, and accidentally sees his mother there, and attacks Hidemi. Despite knowing that this is a line that should not be crossed, Hidemi accepts Yuki. A secret affair with her son, hidden from her husband... What lies ahead in these days of sexual depravity between mother and son...