Кірю Кейкі

Keiki is a kind-hearted, friendly and considerate guy. He cares for his close friends and family, and is, in turn, cared for and liked just as much by them. His kindness is pointed out, by Shouma, as his good trait and as to why girls would have a reason to like or love him.

Keiki also wants a girlfriend and is annoyed by the many couples he sees and is quite envious of them.

He cares very much for his sister Mizuha and spoils her with affection, to the point of being described as a sis-con by Mao

He also has a rare trait as a harem protagonist as he is not very dense. He has been able to figure out the feelings some girls hold for him in some respect, but did not know their perverted sides. He also seems to have quite a bit of confidence/courage when interacting with the girls as shown when he confronts Sayuki about her secret (which he thinks is her romantic feelings for him). He is quite assertive when it comes to finding out who is in love with him.