The friends of Shinya, who often stay over, are secretly attracted to his mother Yumi. One day, Takanori accidentally witnesses Yumi masturbating and can't help but pounce on her, having sex with her. Another night, Takanori presses Yumi again, and Michio also joins in, savoring Yumi's voluptuous body. When the son goes to a training camp, the youngsters gradually start to initiate threesome orgies and climax intensely.
