CosPlayer is this Japanese production company's attempt to combine the words "costume" and "player." Mayumi Misawa has four different costume changes - schoolgirl, gymnast, nurse and maid - and gets to play around wearing each one.

As the schoolgirl, Mayumi masturbates when she's alone in class. As a gymnast, she gets into a sexual wrestling match with some dude who busts in on her during her routine. As a nurse, she gives a dude a full body examination. He returns the favor. And as a maid, she goes above and beyond the call of duty with another guy.

It's pretty straightforward, repetitive, one-on-one sex with the only real variation being the costume changes.