``Your mother is seriously beautiful,'' his friend said, and Masaru began to think of his mother as a woman. One night, Masaru's mother, Miho, invites her husband to have sex, but she refuses and her uncontrollable sexual desire causes her to masturbate next to her husband. She happened to wake up, and Masaru saw her masturbating, and his desire to see her mother as a woman grew stronger. Masaru takes the opportunity of his girlfriend's father being away on a business trip to express his feelings to his girlfriend Miho over and over again. Masaru is overflowing with her desires and thoughts, and in the house where the two of them are alone, her father will soon return, and she intercourses with Miho.