One Piece: Defeat Him! The Pirate Ganzack! (1998)

Luffy, Zoro, & Nami are drifting on their boat without any food to eat. Right until a sea dragon attacked their boat and took Nami away. Luffy & Zoro washed up on shore on a small island. Where they encounter a girl named Medaka. Who tells them, that her island has been taken over by Pirate Ganzack and his crew. Ganzack has enslaved all the men on the island, including Medaka's father. And she'll do any necessary task to save him. To make matters worst, the food on the island is scarce. Which makes Luffy disappointed, but learns that if Ganzack is defeated, he can have more food. So he, Zoro, & Medaka infiltrate Ganzack's base to free the prisoners, find Nami, and defeat Ganzack.