Shiki Ichinose would have never guessed his adoptive father used to be an Oni-hunting Momotarou, much less that the old man walked away from that life just to raise him despite Shiki's dangerous Oni blood. After seeing the only parent he ever knew murdered by a Momotarou assassin, Shiki's blood awakens. Thrust into an ancient conflict between Oni and Momotarou, Shiki will fight to survive, to take his revenge--and to hold back the calamity coursing through his veins...