"Hime Chen! Otogi Chikku Idol Lilpri" centers around three elementary school girls—Nina, Seira, and Alice—who are chosen to become magical idols tasked with saving the fairy tale world, Wonder Story. The fairy tale world is in danger of disappearing because humans have stopped believing in its existence. To restore the world, the girls must collect "Wonderfuls," magical fragments that embody the essence of fairy tales. These fragments are scattered across the human world and can only be obtained by performing as idols and inspiring people through their music and performances.

The girls are guided by a group of fairy tale characters, including Cinderella, Snow White, and Kaguya, who act as their mentors and provide them with magical transformations. Each girl is assigned a specific fairy tale theme: Nina represents Cinderella, Seira embodies Snow White, and Alice is tied to Kaguya. Their magical transformations allow them to access unique abilities and perform on stage as idols, spreading joy and rekindling belief in fairy tales.

As the story progresses, the girls face various challenges, both in their idol careers and in their mission to collect Wonderfuls. They encounter rival characters, such as the dark idol group Black Alice, who seek to disrupt their efforts. The series balances lighthearted moments with themes of friendship, perseverance, and the importance of imagination. The girls grow not only as idols but also as individuals, learning to overcome insecurities and work together to achieve their goals.

The narrative is episodic, with each episode often focusing on a specific fairy tale or challenge tied to collecting Wonderfuls. Over time, the stakes increase as the fairy tale world’s fate becomes more precarious, leading to a climactic resolution where the girls must confront the ultimate threat to Wonder Story. The series blends magical girl elements with idol culture, creating a unique premise that appeals to younger audiences while incorporating familiar fairy tale motifs.