Koza Commerce High School is one of the five high schools situated in Okinawa, Japan.
In the Anime
In the anime, Saya, Kaori, Kai and Mao are shown to attend this high school. Saya and Kaori was in the same class. On the school grounds, Mr. Inamine, one of the teachers, gets attacked by a chiropteran which hoists him up in a tree and drains his blood. Saya meets Hagi who forcefully feeds her his blood in the Biology Lab. That stimulates her chiropteran mode and she slays the monster. Kai arrives on time to witness the incident.