Narrates the story of Kyuuki, a strong, proud fox demon who recently woke up and needs a host and Kamishiro Shin, a normal would be high school student if it wouldn't for "his ability" and for the fact that he got a hold of the black Grimoire that controls Kyuuki's existence.Shin is bound to the book as long as he is alive, thus not only he can't sever his connection to Kyuuki; but those who want the book's power are bound to come after his hide regardless of time and place.