In the enchanting land of the Trump Kingdom, Princess Marie Ange reigns as a wise and benevolent leader, ensuring the happiness of all her subjects. However, their peaceful existence is shattered when a wicked entity known as the Jikochū launches an attack on their kingdom. Resolute in her duty, Cure Sword, a loyal warrior of Marie Ange, valiantly defends her homeland against the evil forces.
As fate would have it, Cure Sword is transported to the human world along with her fairy partner to search for the missing princess. In her quest, she enlists the help of three other fairies to seek out three selected girls who will fight alongside her.
One of these fairies, Sharuru, finds Mana Aida, a bright young girl who serves as her school's student council president. During her school's orientation day at the Clover Tower's observatory, Mana has a terrifying encounter with a Jikochū who tries to manipulate her heart. Fortunately, Sharuru intervenes, gifting her with the power to become Cure Heart. Soon, Cure Diamond, Cure Rosetta and Cure Sword team up with Cure Heart to form the Dokidoki PreCure, and together they must bravely battle to safeguard the hearts of their people from the Jikochou.
