A mysterious man begins targeting women with aggressive sexual assaults, claiming his actions are a necessary "punishment" for their crimes. After breaking the will of a lawyer and a young girl named Kanon, the man finds a devoted follower in Kanon, who eventually lures her own sister into the man's predatory grasp to share in the "punishment."
Kouichi continues his campaign of revenge, systematically breaking the will of the remaining sisters. After turning Nao into a devoted accomplice, he targets the eldest sister, Kyoko, revealing that his quest for "punishment" stems from the total ruin of his own life. Through a combination of manipulation and pleasure, Kouichi forces Kyoko to submit, leaving all three sisters completely subservient to him in a twisted attempt at atonement.