Oo Maou, Shindeshimau to wa Nanigoto ka: Koyakunin, Maou Fukkatsu no Tabi ni Deru

When his boss tells him that the Demon Queen, who offered one of her two hearts to the heroes and sought peace with humanity, has been murdered by a demon tribe that wants to continue the war, Cleto is ordered to take it upon himself to resurrect her. In order to end the war, this simple bureaucrat heads to the territory of the demon tribe with a close associate of the Demon Queen, and the strongest human heroes, who possess the heart necessary to revive her.