The life of a college student is never easy. But when Atsushi is introduced to a nice girl in need of some tutoring by Chidori, an upperclassman that he has a crush on, 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. And 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.
Chidori invites our main hero over to her place, has a drink with him, and fucks him. She says she did it because she's been having some problems with her boyfriend lately.
Our hero also fucks the two sets of mothers and daughters in different configurations (two-way, three-way, and in the finale, six-way as Chidori also joins in). Based on the dialog, both mothers are with husbands.