Having run away from home with nowhere to go, Yuu wanders the streets until she's cornered by a group of rough men who forcefully assault her. They even steal her wallet, leaving her desperate enough to contact her old friend Hitomi, her last remaining hope. Hitomi invites her to her apartment, but upon arrival, Yuu is taken in by a man who is kept by Hitomi as her personal sex slave. With no place else to turn, Yuu is soon sexually dominated by this mysterious, shadowy man. When Hitomi discovers their encounter, she flies into a rage and inflicts even harsher punishment on Yuu.