Every Saturday, Tsumugi was in charge of her son's sexual management. After she got a boyfriend, her son was forcibly separated from her and, unable to control his rage, he assaulted his mother. Seeing his aggressive behavior, Tsumugi felt how much he had grown and her love for him deepened even further. Determined to make her son hers alone, she began seizing control of his nights, refusing to let him have sex with any other woman. As she unleashed her own desires, her desire to dominate him evolved into complete control.