In a secluded village, there was a custom of sacrificing a child with high mana to an evil god once every hundred years. Marc, a boy with white hair known as 'The Devil's Child who summons disaster,' was destined from birth to be the sacrifice.

And so, Marc was sent to the 'evil god' as a sacrifice, but it turned out that over the long years, the legend had merely been distorted; the so-called evil god was, in fact, a great spirit who deeply loved humans—

Favored by the Great Spirit Nerodias and becoming its contractor, Marc chose to leave the village and journey into the outside world.