Synopsis: The Impregnable Demon King's Castle and the Expelled Black Mage of the Hero's Party

During the current era, risking one's life as an adventurer, demon, hero, or demon lord is no longer necessary. The world enjoys peace and conquering dungeons has become a form of entertainment. Thanks to magic, adventurers and monsters can battle with substitutes, making dungeon conquests popular without resulting in any fatalities. After losing his previous employment, Remme, also known as the "Black Mage," faced difficulty in finding another group until he encountered a stunning woman who offered him a job.