One day, the human town was suddenly covered in dark clouds. The troubled townspeople sought help from the Saint, who was revered throughout the land.

And so, Guest, a duke's daughter, was offered as a "Sacrifice for the Demon Lord" to save the country, according to the Saint's prophecy. Left behind in the depths of the eerie Demon Forest, Guest waited for death in fear. What appeared before the trembling Guest was not a giant demonic beast... but Rudolf, a "Demon Lord" who looked like a small child, with horns on his head and wearing a baggy cloak.