Birthplace: Tokyo
Birthday: October 25
Sign: Scorpio
Age: 18
Bloodtype: A

Hisui Kisaragi is a senior high school student at the Ouran Academy, and official of the Tea Ceremony club. To the everyday eye, this reserved, inconspicuous young man is the owner of an antiques shop, whose kin has had business dealings with the Misato family for a long time. In fact, Hisui has been close to Aoi since the two met as little children, being drawn to her warm sincereity and sympathy. He is very loyal to Aoi, and holds a psychologically deep-rooted affection for her, although he hardly speaks his true feelings.

Hisui is the only one of the teenagers to fully understand the dangers that Tokyo now faces. The Kisaragi Clan is revealed to be a family that has killed demons since the days of the Tokugawa shogunate, protecting the city in secret. Since his childhood, he has trained to battle Oni, studying not only Ninjutsu, but Shinto and netherworld incantations. His primary weapons are kunai, or throwing blades. He is the one the Magami teenagers turn to for guidance and knowledge.

Very traditional and slightly self-righteous, brooding Hisui clashes often with Kyouichi Houraiji, calling him a "simpleton" and insulted by the other boy's loud, brash and aggressive ways. Strongly devoted to his teachings and beliefs, Hisui struggles between duty, honor, and affection - especially when Aoi is revealed to contain the Bodhisattva Eye, a power his clan had sworn to destroy.

He keeps to himself, and keeps everything inside, and Hisui Kisaragi seems to know early on that his Star of Fate falls under the Black Tortoise; he is the Vessel of Genbu, one of the deities to protect the Golden Dragon.

Hisui is a descendant of Nagare Kisaragi, brother of Suzuri Kisaragi, from the game Tokyo Majin Gakuen: Gehouchou.