I'm Quitting Heroing, Vol. 1 (manga)

After saving the world from the Demon Lord, the Hero,Leo, discovers that there isn't a place for him in it anymore. The incrediblestrength that made him humanity's greatest asset during the war is just aterrifying threat in times of peace, and he soon finds himself shunned fromhuman society. But if the forces of good won't have him, that means it's timefor him to apply elsewhere' for a job with his former enemy, the DemonLord's Army!