Yumi Kurashina was the wife of the Kurashina household, believed to be far removed from any thought of infidelity. However, she realized that she hadn't had sex with her husband in over a year, and anxiety slowly began to build inside her. Unable to express these feelings to her husband, she could do nothing but endure lonely nights. Yet, she began to feel her mature body pulling her toward something, and finally, Yumi took a decisive step.