Onodera is a playboy, and he never really loves the women he slept with. That is because the one whom he has set his heart upon is his best friend Hiroaki, but he believes his feelings are just platonic. Nevertheless, he tries his best to not allow other women to come near Hiroaki as he thinks they're all after his money. One day, Onodera was asked to become a tutor for Hiroaki's sister, Haruna. After finding out that Haruna actually has a crush on her own brother, will the two become rivals, or...?