In the days of yore, humanity was plagued by a being known as Overlord Diablo, who commanded his hordes of monsters to wreak havoc upon the world.

This villain's reign, however, was not to last. In time, a valorous youth arrived to defeat both Diablo and his underlings once and for all, bringing peace to the realm forevermore.

Such was the tale that Root grew up on—and yet, somehow, he has found himself face to face with the very creatures he's been told were vanquished.

Bereft of a means to fend these monsters off, it is then that he encounters another of their kind—an arrogant, bird-like beast with a seemingly endless appetite.

Hoping that he may be reunited with his family along the way, Root decides to embark on a journey with this mysterious talking monster.

...And thus are his days of peaceful living brought to an end.