At Emiko's home with her stepson Ichitsuru, his older brother returns with his girlfriend in tow. Though confused, Emiko is forced to accommodate the couple as temporary residents. They mock her openly and act however they please. One day, upon returning home, Emiko discovers Ichitsuru having sex with the female houseguest. Overcome with jealousy, Emiko strips off her clothes and takes action to reclaim her son. This impulsive decision becomes the turning point that drastically changes her life.