Aoi has been known for his good looks since he was a child. He has been in an all boys' school for 4 years, and it wasn't unusual for other students to hit on him.
Despite his feminine looks, he uses vulgar language and is rather violent. It is normal of him to use items around him to punish those who try to make a move on him. When we first meet him, he despises homosexuals, and dislikes the fact that due to their age there are numerous relationships (including his best friend, Tominaga, and the student council president).
He later on meets Takahiro Azuma who doesn't seem to look at him with lust or scorn, which interests him. Being with Azuma is apparently the most comfortable place for Aoi. They hang out in the biology lab, since Azuma is in the Biology club, where there are many animals, especially cats.
Aoi has two older sisters, and is rather well-known in his school. He is first seen as a dunce with low grades, but Azuma later on helps him.