I think you misunderstood the concept- she's rubbing her pussy on his back (and then his chest). It was featured in the original doujinshi drawn by the author (this looks better because it has a dedicated artist), where Kawashima does it to the male MC, but then realizes it's kinda meh next to a proper fucking.dont you guys want a girl to rub her butt on your back like a dog with a shit caked ass on hot asphalt