Once there was a Great Gold Pirate called Woonan with a legend that he gathered a third of all the gold in the world. A boy named Tobio who wished to be part of Woonan's crew meets Luffy and his gang and embarks on a journey to uncover the legend. It's the only One Piece film ever produced in traditional cel animation. The first One Piece film should be viewed after Episode 18 of the hit anime.