Shigaraki Kinuyo has been working as a couturiere at her family's fashion shop ever since she was little. With a little help from her talking pet hedgehog, Harriet, they sew custom-tailored outfits made for the many different mythical creatures that inhabit the world of Royal Warrant. To obtain the material to create such outfits, she and Harriet must go on daring adventures together, atop her flying broomstick.