Rin Sahara's an uptight hall monitor who maintains the public order at school. But beneath her straight-laced demeanor, she's secretly horny and wants to have sex with her boyfriend Kouta. Not wanting to compromise her values, she makes do with masturbation for now. Unfortunately, while touching herself in a classroom to a confiscated porn mag, she's secretly recorded by the guy she confiscated it from! What will she do to guarantee his silence?