One Piece: The Movie - Clockwork Island Adventure

Luffy and his crew accidentally rescue an old woman at sea. Fearing that these pirates might kill her, she hastily claims that there is treasure on the island where she lives. Luffy finds this amusing and decides to investigate, but the island the old woman leads them to is filled with traps. It turns out that the island's ruler, Ratchet, is actually the old woman's son. Although the others were initially skeptical about the existence of treasure, hearing a local lullaby ignites everyone's hope for finding it. Even Ratchet proposes joining Luffy and his crew to uncover the mystery of the treasure...