Aono, Kyouko

青野響子

Kyouko is Tsukune's 17-year-old cousin. Characterized as a tomboy with a stubborn streak, she is overprotective of him and appears on the second day of the school festival while searching for Yōkai Academy. Tsukune and his friends try to keep her from learning about the academy's nature and its students, as well as to prevent authorities from discovering she is human. Kyouko manages to enter the yōkai world after being asked to deliver a mysterious package containing the Lilith Mirror. Housing a fairy, it claims to grant the owner any wish they desire, but at the cost of their soul. Later, Kyouko is led to believe Tsukune is involved with the yakuza. She eventually discovers the school's true identity after a turbulent experience with the Lilith Mirror.
In the anime, she is mentioned on a cell phone in the first series and makes an appearance in the 7th episode of the second series, where she tries to decide who should be Tsukune's girlfriend.