Battle of Demons (Japanese: 華鬼, Hepburn: Hana Oni, lit. "Demon of Floral Beauty") is a Japanese novel series written by Risa and illustrated by . As of 2010, the original novel series has sold over 300,000 copies in print. It was adapted into a trilogy of live-action films in 2009, and later a stage play in 2010. It was also adapted into a video game in 2011.