A world of endless demonic civil war - the Demon Realm. The strongest among the demons known as "Demon Lords" battle day-and-night for control over the realm. Kirika and Masha, maids who serve the Demon Lord Maxim, return to their castle to find it destroyed by a rival lord, Lyzenorg. As the only surviving vassals, Kirika and Masha must adventure together with their master Maxim, reduced to a shell of his former self, in order to restore him to glory. Their story of revenge and revival begins here!