Jiro is a member of the Phoenix Pirates. He is the youngest member of the group.
Upon encountering the Straw Hat Pirates, his wounds are attended by Tony Tony Chopper. After his checkup, Jiro asked Chopper to take a look at their captain, Puzzle. Jiro then lead Chopper to a secret compartment in their ship where the captain was recuperating. Chopper, upon seeing Puzzle in such a state, scolded Jiro for leaving him in such a condition. Despite this however, Chopper complied to Jiro's request and did the best he could for Puzzle. After Chopper did what he could, Jiro is informed that Puzzle is still in a critical condition and still needs to heal. After Puzzle Awakens, Jiro is the one who encourages him back to his old self. He also helps Chopper and Luffy when they go assault Lovely Land and the Achino Family. At the end of the Ice Hunter Arc, him and the Phoenix Pirates get back their flag and help the Straw Hats avoid Campachino's ambush.

First Appearance: Episode 326

Source: http://onepiece.wikia.com/wiki/Jiro