In the late Victorian era, there exists a race known as beastkin. They are those who are born with the ears and tails of an animal. Handled by the government from birth, all beastkin children are trained to become the perfect servant for their assigned human masters. Mel is one such beastkin, and her clumsiness and timidity delay her dream of finding a master of her own.

Mel is eventually given to a young author. Her new master is reclusive, keeping only the company of the family maid, Colette, in an expansive mansion. The master is initially indifferent to having a beastkin servant, but their relationship deepens as they learn more about each other and become more like family.