"Miss Kuroitsu From the Monster Development Department" is a workplace comedy set within the fictional evil organization Agastia, which operates in a world where heroes and villains frequently clash. The series centers on Touka Kuroitsu, a dedicated and overworked employee in the Monster Development Department, tasked with creating powerful monsters to challenge the hero Blader. Despite her efforts, her creations often fail due to budget constraints, corporate bureaucracy, and the hero's overwhelming strength.

The narrative explores the mundane yet chaotic daily operations of Agastia, blending satire with humor. Touka's team includes Wolf Bete, a werewolf monster who struggles with his role as a villain, and Akashic, a sentient slime with a cheerful personality. The series also features Megistus, the flamboyant and eccentric leader of Agastia, who prioritizes style over practicality, and Kemurin, a quirky scientist who assists Touka in her projects.

As Touka navigates the challenges of her job, the series highlights the absurdity of corporate culture within an evil organization. Episodes often revolve around her attempts to innovate within tight budgets, manage interpersonal conflicts, and deal with the unpredictable actions of both her colleagues and the hero Blader. The show balances comedic moments with subtle commentary on workplace dynamics, making it a unique entry in the genre of workplace anime.