The primary male protagonist of the series. He's a fairly average person and he doesn't fit the mold of the stereotypical male hero in most harem anime series. For the most part, he's shown to be a fairly good student and isn't prone to emotional outbursts unlike other leading males in harem anime. He's generally well liked and is a member of the photography club at Meiritsu University. He harbors a deep dislike for the Hanabishi clan due to their inhumane treatment of himself and his mother, which was due in turn to that clan's disapproval of his parents' relationship and resulted in Kaoru leaving the clan. Kaoru's mother and father never married and he was an illegitimate child. His back is scarred from when he was tortured with a bamboo cane for trying to prevent his grandfather from burning mementos of his dead mother.

Kaoru belongs to the Hanabishi Zaibatsu family; they gave their commitment and his marriage vowels to a girl in the Sakuraba family (Owner of the Sakuraba Department chain Stores) - Both are as prestigious as each other. Kaoru was dis-owned from the Hanabishi family, causing the planned marriage to be cancelled.

He now lives and studies in Tokyo and has become 20 years of age.

His given name 'Kaoru', translates as fragant as his personality is gentle and kind. He is known for his courteous actions among female characters; however, he can also be abrupt and let them know when something is wrong.

Due to his child-hood experiences, he became a semi-recluse while studying in Tokyo; Aoi sparks light into his life, when he is lower than ever before and extremely lonely.