Yamete Kure, Tsuyoi no wa Ore ja Nakute Ken nanda......!

Crow Titus is the greatest hero in the land. He's gallant, brave, and adored by all—the perfect warrior. Or he would be if not for one minor detail: it's all an act! He'd like nothing more than to take it easy and live a quiet life, preferably with an above-average girlfriend and a significant amount of wealth. Unfortunately, his cursed blade takes control of his body in its quest for its favorite meal—souls. But thankfully, it prefers to feast on the wicked. So in order to keep his curse a secret (and his sword satiated), Crow must keep up the act as a hero and slay the dangerous aetherborn that have been plaguing humanity for a thousand years. Otherwise, his sword might turn its hunger on the innocent and turn Crow into a mass murderer!

(Source: J-Novel Club)