Mother Reiko finds herself drawn to her grown son, Koji. Though she knows it's wrong, her uncontrollable desire compels her to tease him with lewd words and provocative behavior, yet Koji remains completely unresponsive. Driven to the edge, Reiko can no longer hold back and exposes her own depraved state. From that moment on, Koji begins to see his mother as a woman. In response, Reiko suddenly changes her attitude, becoming cold and distant. Unable to endure the torment of this unfulfilled tension any longer, Koji finally takes action.