Top student Mary Tachibana visits her private tutor's house for exam preparation, but a perverted teacher is lying in wait. He has hidden cameras set up, along with restraints, vibrators, and electric massagers. Mary is blackmailed with masturbation photos, mercilessly toyed with using sex toys, and ultimately forced into brutal intercourse. Later, the tutor visits Mary's home, confirms her mother is away, and begins plotting a new scheme.