The pearl Lucia chases across the human world is just an excuse, what hooks you is watching a mermaid princess discover that friendship and love are louder than any magic song. The combat system doesn't matter; what matters is that every transformation feels earned, every duet between Lucia and her friends carries weight that most mahou shoujo reserves for final episodes. This show trusts that colorful, earnest, and sincere can carry 52 episodes without irony or apology.

Lucia is the mermaid princess of the North Pacific, one of seven mermaid kingdoms. One night a boy tumbles off a ship, and she hands him her magical pearl. To get it back and keep the mermaid kingdoms safe, she heads into the human world. There she relies on the power of music to defend herself and her people against a spreading evil. The series is a musical magical girl story that mixes adventure, comedy, fantasy and romance.