Akisu

Akisu is a character that appears in the second movie.

History
The Straw Hats meet him and Borodo, who call themselves the Thief Brothers, while looking for their stolen ship. It's known from the beginning that the two aren't brothers by blood since Borodo found Akisu floating in the ocean when he was just a baby. However, they consider themselves brothers.

As they reach Clockwork Island, it becomes apparent that this is Akisu's original home island. This is made more evident by Akisu's natural know-how of clockwork. Akisu manages to save Borodo after Bear King tries to kill him near the climax of the film.

After the Trumps are defeated, Akisu is reunited with his parents who reveal they sent their child out to sea to avoid being ruled under the Trump Siblings. Despite this, Akisu decides to stay with Borodo.