In the rule of The Melodia Kingdom, Queen Musette was collect the Twenty Mussetes of Hearts. But a mystetious villain named King Pierrot from Shadow Kingdom was destroy the Melodia Kingdom. Then after that Queen Musette was destroyed, the twenty Hearts of Musettes are missing and were scattered. On the other hand, the Twenty Museruns will find the Twenty Warriors in the Earth to find the Pretty Cure to save the Melodia Kingdom.
There is a prophecy about the Pretty Cure that goes like this:
Twenty 15-year-old's shall answer the call,
Without the Elements and Cards, the world shall fall.
The Fantasy, Legend, Dreaming, Giggle, Soul, Romance, Warm, Quirk, Nova, Shadow, Gleam, Life, Pikelet, Time, Diva, Ice, Juice, Sensual, Fauna, and Luck shall disappear,
The first line refers to Hoshimiya Saki, Moribira Maya, Aokikawa Linx, Kusukusuwarai Riki, Murasaku Yuba, Akaharu Gwen, Chiyaki Hime, Hatsune Maru, Honoko Asami, Momomiya Miku, Akari Tsukino, Koyanagi Mizuke, Kitagawa Mikanki, Hoshizora Pikaru, Midori Shion, Ongaku Monique, Shinzuki Fuyu, Koizumi Jun, Hanada Tara, and Yotsuno Kiera who all agree to become the Legendary Warriors, Pretty Cure.
Each of the girls need to possess the Twenty Musettes of the Hearts: Fantasy, Legend, Dreaming, Giggle, Soul, Romance, Warm, Quirk, Nova, Shadow, Gleam, Life, Pikelet, Time, Diva, Ice, Juice, Sensual, Fauna, Luck and without them, the Melodia Kingdom and the Universe will be destroyed.
Fantasies, Legends, Dreamings, Giggles, Souls, Romances, Warsm, Quirks, Novas, Shadows, Gleam, Life, Pikelets, Timed, Divas, Ices, Juices, Sensuals, Faunas, and Luckiness will disappear when the world is destroyed.
If the Pretty Cure can't believe in themselves and have hope that they can defeat King Perriot, then the world will be destroyed.