Tokyo Ravens is a Japanese light novel series written by Kōhei Azano and illustrated by Sumihei. It was adapted into a manga series in 2010. In the "Great Disaster," Japan has been thrown into chaos by onmyouji (a kind of magician). Harutora Tsuchimikado was born into an onmyouji family, but has no power whatsoever. His childhood friend Natsume (another member of the Tsuchimikado family) appears to him one day to take him up the promise he made long ago to become her shikigami (familiar). A battle between onmyouji is about to begin.