Ten years after losing her husband, Sayoko raised her only son, Hiroyuki, single-handedly. Eventually, Hiroyuki started working at his uncle's company, and the family began to enjoy a peaceful life. However, this tranquility didn't last long—Hiroyuki made a serious mistake at work. Upon learning of it, his uncle, Yoshihiko, stormed into their home and demanded that Sayoko take responsibility. Helpless and naive to the ways of the world, Sayoko had no means to respond. Seizing the opportunity, Yoshihiko grew increasingly bold, targeting her voluptuous figure and pressuring her into submission.