The Ainu portrayed in the film are an indigenous people who primarily live in Hokkaido, the northernmost Japanese island. Up until the late 19th century, both Ainu and Hokkaido were referred to as Ezo. Kamui Nupuri means "mountain of the gods" in the Ainu tongue. Hiroyuki Sanada, is better known for his various live-action roles. This film was the first and only time he worked on an animated film.