航海王：海肚脐大冒险

The Straw Hat crew catches a treasure chest while fishing during their voyage. Upon opening it, they find a piece of paper that reads, "When you see the navel of the sea, jump in. There lies the legendary treasure." At the same time, a large hole appears on the ocean's surface, resembling the belly button of the sea. Nami, Usopp, and Sanji decide to venture into the Sea Navel to search for the treasure. Meanwhile, Luffy and Zoro, who stayed behind on the ship, find a mysterious message in a bottle. Luffy and Zoro, who are swept into the sea, encounter Mero and Ham, a girl and a boy who live in the Sea Navel. At the same time, Nami and Usopp also encounter the ghost of Captain Joke. While Zoro remains locked in battle with the divine beast, Mero provides support for Zoro. In the end, with the assistance of Luffy and the others, they successfully defeat the ghost of Captain Joke.