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 an anime series on October 9, 2013. Funimation is simulcasting the series on their website.
In the "Great Disaster", Japan has been thrown into chaos by onmyouji. Harutora Tsuchimikado was born into an onmyouji family, but has no power to sense spiritual power whatsoever. His estranged childhood friend appears one day to take him up on a promise he made long ago to become her shikigami (familiar).