Two girls, Hibiki and Kanade, junior high school students, have known each other since they were children.

As they grow up, they tend to argue more and more.

One day, a fairy called Hammy comes from the musical country "Major Land" to look for the legendary warriors called Pretty Cure.

Hammy asks Hibiki and Kanade to become Pretty Cure in order to protect the earth from an evil force.

This force is planning to destroy the world by changing "Happy melody" into "Unhappy melody" in the legendary musical score.

When the two girls are aware of a danger, they become Pretty Cure!