Popular idol Kokomi Naruse plays a high school girl who goes undercover in an O-back position! She's supposed to use her proud ass to punish the evil organization that's terrorizing the school... but she ends up being captured instead! Kokomi is relentlessly attacked in the O-back position and is on the verge of losing consciousness. Will she be able to get out of this pinch with a variety of killer plays that make use of her ass, such as ass-jobs and face-sitting?!