The Mermaid And The Captain

Stella had been kidnapped by a group of pirates. It's impossible to escape. She doesn't have legs.
Frank is the captain's son. He wants to help her. But he can't let her go.
They have a secret romance.
There's no way for Stella to break out the cage. All she wishes is the grow legs. It would be easier for her to escape. But she doesn't wanna leave Frank.
One day, Stella wakes up with legs. She surprises Frank. Now their relationship can get serious.
Frank is trying to hide Stella from the captain. Stella has the chance to be free. And Frank wants to go with her. But he can't leave his dad.
The captain notices that the mermaid broke out her cage. So he's looking for her. Stella and Frank are finding places to hide.