Dead Rock

Story:

Across the different layers of the Demon Realm, the one place every demon and monster aspires to enter is Dead Rock, a training institution where they can learn how to become Demon Kings. For those who manage to graduate, this means being offered by God, the supreme ruler of all the realms, the chance to pass to the human realm and claim a piece of it as their own. However, a young and mysterious demon named Yakuto has entered the special entrance exam with a different objective.