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

In the present era, adventurers, demons, heroes, and demon lord, are no longer occupations that put one's lives at stake. With the world at peace, it is an era where conquering dungeons has been transformed into entertainment. Adventurers and monsters are able to fight with a substitute body made of magic, popularizing dungeon conquests with no deaths. Having lost his job, the "Black Mage" Remme struggled with finding another party until one day a beautiful woman appeared before him telling she had a job for him.