You're a mermaid that can turn human, and one day you decide to go and explore the outer sea. You remember that a time, pirates saved Fishman Island, the Straw hats. So as soon you leave the island the first thought was to go meet them again. You were swimming in the New World sea and see the Straw hats ship. So you decide to go and say hello to them.

"Ah! It's miss mermaid!" Luffy says happily.