After a brief appearance by him in the middle of the series he begins proclaiming that he 'loves' Misaki, but that was only after he found out how close he and Usagi were. He is generally cold and disapproving towards his brother, though no one really knows why.
Shortly after meeting Misaki, he finds that Takahiro has gotten engaged. Usagi is Misaki's tutor for the upcoming entrance exams, and a very close friend of Takahiro (he, in fact, harbored an unrequited love for Takahiro for a long time). His nickname is "Usagi", which means "rabbit" in Japanese.