The plot revolves around a girl called Mikiko "Kuromi" Oguro who grows up watching the fictional anime Luis Monde III. She decides that animation is something she wants to do, and so enrolls in animation school. When she gets out of school, she is delighted to find a job at a small animation studio named Studio Petit. The director of the studio shows her around and gives her the nickname "Kuromi," a name meant to abbreviate her own.

Very soon after Mikiko arrives the director falls seriously ill and leaves his post, but not before he appoints Mikiko with the job of Production Desk Manager, on the second episode of the studio's current anime, Time Journeys.

The audience follows Mikiko's frantic attempts and schemes to convince the studio's artists to work harder and produce their key frames in time to send them for production.