A cabbie gets his kicks by blackmailing, raping, and storing women in his "collection". He just moved to a new town to find new victims. He picks each girl up many times and follows them around, seeing if they slip up once and then uses that to blackmail them. His first victim is Satsuki, a member of the archery club. From there, he gets with a couple twins, a swimmer, a cheer leader, and finally settles on your mom.