For Kobayashi, every workday is the same tiring routine, followed by a night of drinking with coworkers to let herself loose. However, her stale life changes one morning when she is greeted at her front door by the huge face of a dragon. Introducing herself as Tooru, the dragon transforms into a young woman in a maid outfit. Having met Kobayashi drunk in the mountains the night before, she accepts Kobayashi's invitation to live with her as her personal housemaid.

Kobayashi-san Chi no Maid Dragon follows the daily life of Kobayashi, her dragon maid Tooru, and various other dragons as they move past their differences to grow closer together.