In Sukoyaka City, a place known for its refreshing atmosphere, Nodoka Hanadera, a cheerful middle school student who often gets sick, has just moved there. She quickly becomes close friends with her new classmates: Chiyu Sawaizumi, an athletic and kind-hearted girl whose family runs a hot spring inn, and Hinata Hiramitsu, a lively and fashion-focused girl who is the daughter of a veterinarian.
Not long after settling in, Nodoka discovers a sick puppy in the forest together with three magical talking creatures named Rabbirin, Penguitan, and Nyatoran. They explain that the puppy, Princess Latte, can only be saved by defeating a nearby monster called a "Mega Byogen" and purifying the land it has tainted. Even though she has no special abilities, Nodoka is determined to help Latte.
Impressed by her determination, Rabbirin makes a contract with Nodoka, giving her the power to transform into a Precure named "Cure Grace." With this new strength, Nodoka fights the Byogen, restoring the land and healing Latte.
As the Byogen keep attacking along with their leaders, Penguitan and Nyatoran also find their human partners in Chiyu and Hinata, empowering them as "Cure Fontaine" and "Cure Sparkle." Together, the three Precure and their animal allies must join forces to battle the Byogen and protect the world from their corrupting influence.