Kawahara Youko is a calm and somewhat naive full-time homemaker who supports her husband Satoshi, a local government employee. Lately, due to Satoshi's frequent business trips, Youko has been feeling sexually frustrated. Moreover, being in her prime, her sexual desires have been on the rise. During one of Satoshi's brief returns home from his business trip, they engage in a passionate night. They become aware that Daisuke, their son, is secretly observing them, but instead of reprimanding him, they choose not to criticize. In fact, they accept his presence without judgment and even express concern about his increasing sexual desires. Driven by an abundance of affection, Youko decides to take care of Daisuke's sexual needs, believing it to be the right thing to do. However, this act unintentionally intensifies his physical desires and emotions. Ultimately, Daisuke loses control and crosses intimate boundaries with her. With Youko already grappling with pent-up frustration and her sexual desires increasing, she gets increasingly ensnared in his growing demands.