One day, Tsurara is attacked by her stepfather, her mother's new husband. She resists with tearful eyes, but her stepfather licks her face endlessly and kisses her. His persistent cunnilingus makes her cum... something inside Tsurara goes haywire from that day on... Eventually, she begins to crave her stepfather's dick and gives it to her male friends... and Tsurara becomes useless without her stepfather's dick.