He seems like the rebel who loves to pick fights, but he’s actually pretty honest and passionate and Kon also states that Nagisa is unlikely to accept people's challenges. Although Yuya and Nagisa tend to get into fights, Azusa claims that Nagisa is good at heart which is revealed by the fact he even made food especially for Yuya on her first night in the dorm and tells Yuya not to worry so much what other people think about her. He quickly realizes Yuya has a crush on Azusa but it is unclear whether he is trying to hinder a relationship between them or encourage it. He has two younger brothers and one younger sister. He’s the oldest. Maybe he entered a boarding school like Natsuka to get away from his noisy household of kids.