"This is the story of the year that he and I lived."

Kishimoto Mitsuharu is an 11 year old boy was born into a family that has exorcised youkai for generations, but hates them and has no skill for exorcising them either. Since the death of his grandfather, his only family, he has to endure pranks from mean relatives and youkai.

One day, a violent and blunt giant youkai who hates humans, named Kochi, appears,

He has a cursed arrow stuck in his back and says that Mitsuharu holds the key to breaking the curse that was placed on him, but apparently Mitsuharu is also under a "curse"...