A continuation of Onegai My Melody.

The Straw Hat Pirates enter the rough seas of the New World in search of the hidden treasures of the Pirate King, Gol D. Roger－One Piece. On their voyage, the pirates come across a terrifying, powerful man, former Marine Admiral Z. Z is accused of having stolen the Dyna Stones, weapons believed to have the power to shake up the New World. The Marine Headquarters believes Z is about to use it to end the pirate era, and with it, the lives of many innocent people. In fear of such a phenomenal event, marines start to take action against the former admiral. Even if it means stumbling upon marines and the navy, the Straw Hat Pirates decided to chase after Z and stop him from causing havoc. As they continue to embark on their ventures, the pirates bump into new and familiar acquaintances.

Luffy and crew go to an island searching for a legendary sword, said to be the most expensive in the world. Soon attacking marines and beautiful maidens split the crew. Zoro betrays the crew to help an old friend, Luffy and Usopp wander through a cave, and the rest help a village fight marines. When Zoro defeats Sanji he takes the sacred pearls that are the only defense against the evil sword that will plunge the world into darkness. (Source: ANN)

A girl named Olga is pursued by both the World Government and a man named Mad Treasure, as she is the only one who knows the location of the Pure Gold, a substance that can buy the entire world. Olga ends up sailing with the Straw Hat Pirates, and they journey to find the Pure Gold on the lost island of Alchemi, which is located inside the stomach of a large angler fish named Bonbori. (Source: IMDb)