She has sex with anybody

Kazuhiro Sayama finally gathers the courage to confess to his crush, Erika Sakurai. She responds by immediately having sex with their gym teacher in front of him. It turns out that the girl of his dreams is a voracious sex addict and she's especially into exhibitionism. The two strike a deal: Kazuhiro will become Erika's personal cameraman, filming every one of her sexual encounters. He gets to watch the girl he likes in every lewd situation imaginable, with only one catch—he himself may not have sex with her. Will Kazuhiro be content with their arrangement, or will he shoot for something more?