Learning the Hard Way (2007)

The life of a college student is never easy. But when an upperclassman introduces Atsushi to a nice girl in need of some tutoring, life is about to get a little more rewarding for him. Not only is he spending time helping out a cute coed, but she happens to have a sexy mother to boot. Little does he realize at the time that the two will fight over the slide rule in his pants. As time goes on, not only are the mother and daughter still duking it out over Atsushi, but another mother-and-daughter pair get in on the action.