A world where terrifying demons roamed killing and slaughtering all living beings on earth.

A story about how a person totally unrelated to any of it (or so he thought) gets involved after lifting an old sword full of rust. "THE SEALED SWORD was it supposed to be difficult to lift? Well, it failed its second purpose as well. Of course, the first was being a proper sword. It butchered that."

Kai, our protagonist, not knowing what the sword in his hands truly is, starts his journey slowly discovering the truth