Iris is a teenage girl who likes to sing and help others. However, when she sings, strange events happen. Encouraged by her best friend, Iris ends up auditioning for a girl rock band, but her power destroys the room and she is later attacked by two strangers. The judges at the audition, Talia and Auriana, come to help her, and they explain to her that she is actually a princess with magical powers that must save her kingdom of Ephedia from the clutches of Gramorr who has taken over. The only way to save it is to master her powers and to find the Oracle Gems of the Royal Crown of Ephedia, which are scattered across the Earth. Over the course of the series, the three girls try to live ordinary teenage lives as rock stars of the all-girl band "LoliRock", while training Iris in secret. But when Gramoor sends Praxina and Mephisto and has them summon monsters to cause chaos, the girls must work together as magical girl warrior princesses.

After defeating Gramorr, the princesses are back on Earth where LoliRock is about to go on a world tour, but their tranquillity is short-lived. Determined to avenge the death of her brother Mephisto, Praxina has become more powerful than ever and has set her sights on Earth. LoliRock must now protect the planet as they travel the globe on tour.