Mariko, a high school girl, fell in love at first sight with Ken, a single man she happened to see on the train. Her selfish and self-centered feelings grew stronger each day, leading her to barge into his home repeatedly. Initially reluctant to engage in romance with a woman, Ken found himself moved by Mariko's repeated cute and innocent advances, eventually leading to them living together. One day, Ken left Mariko with her collar attached to a leash tied to a pillar, making her stay home alone, and plotted with two of his bad friends to gang-rape her.
