Reiko is a single mother raising her son alone. Now a university student, he spends his time playing around instead of helping out at the soba restaurant run at home. Seeing Reiko's struggles, her son's friend, Shiro, offers to work part-time for her. Shiro, who secretly sees his mother's image in Reiko, wants to help her, but harbors a twisted desire. And then, after work, he tells Reiko his mother...