Itsuka Tenma no Kuro-Usagi

, is a Japanese light novel series by Takaya Kagami, with illustrations by Yuu Kamiya. As of January 20, 2011, 7 volumes have been published by Fujimi Shobo under their Fujimi Fantasia Bunko label. The series also have a spin-off series, Kurenai Gekkou no Seitokaishitsu (紅月光の生徒会室?), which as of April 20, 2011, has 3 volumes published. 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, and is scheduled to air in July 2011.

Plot
Kurogane Taito is a freshman in Miyasaka High. After an injury that prevented him from practicing karate, which he excelled in since elementary school, he had always believed that he was an ordinary, regular guy. However, due to a forgotten promise exchanged with a beautiful Vampire, (Most Ancient Sorcerer) named Saitohimea, nine years ago, he was in fact no longer ordinary. Taito later went on to regain his memories after a certain incident, and was reunited with Saitohimea. Along with unlikely allies, Kurenai Gekkou, Miyasaka High's student council president and a genius bent on avenging his parents, and Andou Mirai, a cute lightning demon and familiar of Gekkou, they have to contend against Gekkou's twin brother, Kurenai Hinata, who sought to resurrect the powerful Vampire (Most Ancient Sorcerer) Bahlskra. Unknown to them, their destinies were already woven and foretold in an ancient prophecy of epic proportions.