One Piece: Oounabara ni Hirake! Dekkai Dekkai Chichi no Yume!

Three children held aboard the ship of the pirate Zap carry a secret inherited from their late father, a treasure hunter: the location of a fortune he spent his life seeking. They persuade two weary pirates, Bonnie and Max, to help them escape in exchange for a share of the treasure, only for their flight to bring them straight into Luffy and the Straw Hats.

The Bayan Pirates are hunting the same prize, and soon Luffy and the eldest child, Amanda, are captured. Amanda has always resented the adventures that kept her father away from home, but the struggle over the treasure forces her to confront what he truly wanted to leave his children. For the Straw Hats, saving the siblings means defeating another pirate crew and uncovering a father’s final dream.