He first appears chasing the Straw Hats into Ruluka and purposely missing them, while employing his fighting technique called Finger Bomber - the power to flick coins really fast and with a very destructive impact.
He is later seen as a child trapped in the Rainbow Mist and as captain of the Pumpkin Pirates. It is revealed that he is Henzo's childhood friend. When Wetton burned down Ruluka, he and his other friends, minus Henzo, stole Wetton's ship, the Tarielishin and drives it into the Rainbow mist.
Upon meeting the Straw Hats and Henzo in the rainbow mist, he does not trust them, however later, he wanders off into the rainbow mist with Luffy and is trapped, until they can manage to find an opening. A few moments later, the Rainbow Mist collapses thanks to Wetton's actions (blowing up the Rainbow Tower, connecting the outside world with it). Upon escape from the Rainbow mist, the Straw Hats cannot find Rapanui or his friends.
However, he later reappears as a marine commander and arrests Wetton for stealing pirate's treasure and after Wetton confesses to have been a pirate.
He also says he will arrest the Straw Hats, but he then theatrically exclaims they have no room on their ship with Wetton's people and how backup could takes several weeks to arrive and lets them go. It is later revealed that he's the author of the Rainbow Mist books from Volume 1 to 10.
