He use to work under Tom, the best shipwright in the whole world, and the one who built the second ship "Thousand Sunny" for the Straw Hat Crew. His dream is to go to the "end of the high sea" with his "dream-ship" that he built himself. He joined the Straw Hat to see through where Thousand Sunny will take the crew to along the adventure. As a shipwright for the crew, he is responsibel for maintenance, remodeling and repair for the ship. He is great at not only ship jpbs, also developing wepons. An incident resulted in his body being heavily damaged, so he augmented himself into a cyborg, who owns mysterious gimmick inside his body in fact that he is a "superhuman."
