This precure is about 4 girls who are chosen to be the melody stars after the queen of Star Diamond has chosen them to find the missing diamond song stones.
Niriku is a student at Songheart academy where she learned to be a popstar along with other girls who auditioned for the popstar melody. A contest for the most popular singers in songheart academy. One day niriku had a dream. 4 princesses from the kingdom dreamsong, appear to Niriku. The 4 princesses told her that their kingdom holds 4 gems, the sapphire gem, the diamond gem, the emrald gem, and the crystal gem. Each gem is protected by the melody necklaces. Each necklace contains a gem. 1 necklace contains a sining power. 1 day, an evil organization, has plotted to take the necklaces and rule earth. Things will start to disappear, lands will no longer exsist, and earth will be destroyed, once the necklaces are taken. In order to restore the land, Queen of dreamsong goes to earth to find 4 girls to help stop the organization. Now, the girls must become sing idols, and harness the 4 powers of the necklaces to stop the organization.
Niaku is the 1st character in the story. She is 14 years old and has light blue hair before her transformation. She also has the gift of song and the power to use her voice from the necklace that contains her gem. She is smart, confedient, serious, messy, and likes to spend most of her days reading a good book instead of being off on an adventurous journey. Her hair is light purple after her transformation.