Catch you, deep sea mystery

Jungkook is a pirate with all his heart. He sailed all over the world already, found many treasures and experienced many adventures. But there's one thing that keeps him on his ship. A story about beautiful creatures that live deep down in the ocean. His mother told him many fairytales about the ocean when he was young. And so he grew to love the ocean. His mother passed away when he was just a preteen. On her deathbed he promised her he would find a Mermaid for her. Since then he is on the hunt for one. He wants to show the tail to all the people in his village that called his mother crazy. So what happens when he finds a young merman or rather the merman finds him?