Fuguushoku [Kanteishi] ga Jitsuwa Saikyou Datta: Naraku de Kitaeta Saikyou no [Shingan] de Musou Suru

In a fantasy world where "jobs" are god-given from birth, heroes are born, not made... and Ein's job of "Appraiser" has put him about as far from the "hero" pedestal as possible. Used, abused, and eventually abandoned by his fellow adventurers, Ein decides it just isn't worth going on... Lucky for Ein, though, the end may just be the beginning... and a new lease on life. Turns out, his "worthless" job may just be the key to becoming a hero after all...

(Source: Kodansha USA)