Matsura Yuki is a 39-year-old mature woman. Discovering that her shy teenage son has a habit of peeping, she decides to expose her masturbation to him, allowing him to watch. Her intention is to awaken his sense of guilt. Yuki provocatively offers her breasts to her son, enticing him. Overcome by his mother's bold actions and allure, the son grows increasingly aroused and erect. A strange, complex relationship unfolds between mother and son.