After her husband moves to a regional area for work, Shino Oishi turns to masturbation to satisfy her desires. By chance, her son Ichihira discovers her, causing him to see her as a woman for the first time. From then on, Ichihira forces Shino to wear revealing lingerie and treats her as his sexual object. Though Shino inwardly knows it's wrong, she gradually succumbs to her son's desires.