Boukensha Zettai Korosu Dungeon - MangaDex
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Dungeons. A romantic setting. However, that’s only for adventurers. Cleaning, replenishing supplies, and dealing with complaints. Aine and Nacht work hard behind the scenes as floor staff in the dungeon. Damn adventurers. The dungeon staff now turns its fangs on the adventurers who gather together while not caring about the troubles of others!

Dark comedy about two girls trapped in worst dungeon of all time (job). With the quest to stop working, our protagonists find new ways to convince immortal adventures to stop coming and stop making the mess.

If anime “dungeon people” is the light side of dungeon managmet occupation this is defenietely a dark side.