Hibiki and Kanade are two friends who grew up together in Kanon Town. Very different in their personalities, they share one thing in common: A connection to music. No matter how different they are or how much their differences cause them to quarrel, they both continue to share loving hearts. One day they meet Hummy, who is sent to the Human World from Major Land to collect the scattered notes of the Melody of Happiness. They have to instantly transform into Pretty Cures to resist the threats and evil music from Mephisto. Can they stop the Melody of Sorrow from disrupting their peaceful town, and can their warped friendship measure up to the bonds of Pretty Cure?

Le Royaume de Crystalia est sous la menace de l'empire des Ténèbres Yodonheim et pour y échapper, la princesse Mabushina s'enfuit sur Terre avec cinq pierres précieuses dont elle souhaite confier les pouvoirs à cinq guerriers qui pourraient lui venir en aide. Tandis qu'elle n'est parvenue qu'à réunir quatre combattants, le pro-gamer Izumi Tametomo, la jeune athlète Hayami Sena, l'acteur Oshikiri Shiguru et la médecin Oharu Kiyo, les forces de Yodonheim commencent à attaquer la Terre. Le jeune lycéen Atsuta Juru va alors devenir malgré lui le cinquième Kiramager.