In the musical Major Land, a fairy named Hummy is due to sing the Melody of Happiness, which is to spread cheer throughout the land. However, the land is attacked by the evil Baron Mephisto and his assistant, Siren, who plans to turn it into a Melody of Sorrow. The goddess of Major Land, Aphrodite, scatters the Notes that make up the melodies throughout the land to keep them safe, and sends Hummy to Kanon Town to seek out two best friends to become Pretty Cure. Meanwhile, Hibiki Hojo and Kanade Minamono, two girls who used to be best friends, have not gotten along with each other for a while. Siren attempts to steal the Golden G-Clefs within their hearts; the power within them prevents it, but she instead discovers a Note inside their favorite record and transforms it into a monster known as a Negatone. Noticing their hearts sync up perfectly, Hummy gives Hibiki and Kanade the ability to transform into the Suite PreCures, Cure Melody and Cure Rhythm.