Itsuka Tenma no Kuro Usagi (いつか天魔の黒ウサギ?) is a Japanese light novel series by Takaya Kagami, with illustrations by Yuu Kamiya. As of May 2010, 6 volumes have been published by Fujimi Shobo under their Fujimi Fantasia Bunko label. A manga adaptation by Shiori Asahina started serialization in the shōnen manga magazine Monthly Dragon Age on October 9, 2009. An anime adaptation has been announced.
- "Moon Phase's news about Itsuka Tenma no Kuro Usagi anime adaptation". October 5, 2010. Retrieved October 8, 2010.