Whilst running to the first day of her new school, the happy-go-lucky Miyuki Hoshizora encounters a fairy named Candy, who leaves behind a pink book. As Miyuki has trouble introducing herself to the class, her classmate Akane Hino helps her to break the ice. As Miyuki checks out the library later that day, she discovers a mysterious entrance, taking her to a strange place where she learns Candy is being chased by a wolf named Wolfrun, who starts making the people in the town fall into despair and steals their 'bad energy' with a goal of ressurecting someone named Pierrot. As Miyuki strives to protect Candy, she is given a magical item known as the Smile Pact, using it to transform into a PreCure named Cure Happy. As Miyuki becomes reluctant to fight, Wolfrun summons a monster known as an Akanbe to fight against her, but with help from Candy, Miyuki manages to realise her power and defeat it, receiving an item known as a Cure Decor. As Wolfrun retreats and happiness returns to the townspeople, Miyuki decides to help Candy in her quest to recover Cure Decors and save her kingdom.
星空みゆきは、絵本が大好きな中学2年生。転校してきた彼女は、その初日から遅刻しそうになっていた。そんな時でも、爽やかな天気に気分が良くなっていた彼女だが、そこに空から本が降ってくる。
Miyuki acaba de mudarse a la Colina Arcoiris cuando se encuentra con un hada, Candy. Tras esto, Miyuki visitará una librería mágica donde verá que Candy esta en peligro e ira a salvarla. Así, ella consigue su Polvera Sonrisa, transformandose en Cure Happy.
Quand le royaume magique de Jubiland est envahi par un empereur maléfique, Candy, la petite fée, recrute cinq jeunes filles pour former une équipe de super-héroïnes.
