Yuusha kara wa Nigerarenai

In an age where humanity is losing against the Demon King's army, everyone has been searching for a "Hero." Solo, a thief creeping around at the bottom of society, hears a rumor: "On a certain hill there's a "Holy Sword" that only the Hero can pull out. Aiming for a quick fortune, Solo tries to steal the sword—pedestal and all—but for some reason, the "Holy Sword" comes out. Treated as the "Hero" for having drawn the Holy Sword, Solo is poised to face the fate of the entire world.

(Source: Kadokawa, translated)