An evil mermaid emperor has taken over the kingdom of Meralore and is planning to take over the surface world next, and he starts doing so by submerging Umi City! The Mermaid Circle, Coral and her friends, Finnius and Kai, seek help from Azure, The Blue Mermaid. Azure knows the only way to save Meralore, and that's to get La Perla de Madeline. But it's in the Umi City Museum. When the evil mermaid emperor learns of this, he places a dark spell under the Pearl and his victims, Team Umizoomi. Will The Mermaid Circle and Team Umizoomi prevail? Maybe an unexpected helper will know the way.
- Team Umizoomi
- The Mermaid Circle
- Emperor Abyss
- Princess Aqua
- The Blue Mermaid wasn't call Azure in The Legend of the Blue Mermaid. Yet when her name is said, nobody is surprised or confused by it.