Suzu, a college student, works as a private tutor for her childhood friend, schoolgirl Urara. The two share a bond like real sisters, supporting each other in their daily lives. One day, Suzu's boyfriend, Tetsugaku, begins taking an interest in Urara. Tetsugaku, who runs with a gang of thugs, had manipulated the innocent Suzu into a relationship. He sees Urara as a sexual plaything and plots to sell her off to his gang members to raise money. Soon, Suzu is dragged into this nightmare as well, becoming an object of desire for the group. Thrown into a sea of debauchery and lust, the two girls' fates spiral downward into ruin.