The film’s story is set in the Doll Kingdom where dolls dwell. In the story, the Pretty Cures are watching a doll play about to start, when the dolls suddenly start talking. “Please rescue our kingdom!” the ballerina named Tsumugi says, and she leads the Pretty Cures to the Doll Kingdom. There, the Pretty Cures thought they would be surrounded by cute stuffed animals, but instead they find a mysterious man named Black Fang who is attacking the kingdom, and he captures Tsumugi. The country normally filled with happiness is hiding a sad secret, and the Pretty Cures must help save the day.

(Source: Pretty Cure Wiki)