In Barbie in A Mermaid Tale 2, Good Morning Oceana was celebrating the one-year anniversary of Princess Merliah's arrival to Oceana. Two seahorse viewers, who are fans of Merliah, admire her as she is shown on screen.
Remo explained that Merliah is Queen Calissa's daughter, but, because Merliah's father is human, she was born with legs. For Merliah's safety, Calissa gave Merliah to Merliah's human grandfather, Break.
Soon after, Remo explained, Calissa was imprisoned by her evil sister, Eris. Eris was tyrannous, and ruled over Oceana for years. Seeing Eris scared the two seahorses, but Remo continued and talked about how Merliah saved Oceana, and accepted her true self. The seahorses watched amazed as Merliah transformed into a true mermaid. Eris was caught in one of her own powerful whirlpools, and Queen Calissa began to rule Oceana with love again.
Calissa gave Merliah a magic necklace to allow her to become a mermaid or human whenever she wished. Remo finished by saying Merliah was a superstar in both the human and mer-worlds, and that she would be competing in a surf competition that day. He finished by wishing happiness to Oceana, and the seahorses sang along to "Queen of the Waves",