The Straw Hats visits an island, known as Mecha Island, where a fisherman sings an old folk song about a Golden Crown. Searching for that mysterious treasure, they find a hidden entrance into the island. The island's leader, Ratchet, impressed with the find and in search of the Golden Crown himself, invites the crew to join him in his search and the crew along with Ratchet and his henchmen enter the cave. As it turns out, the islands true form, is that of a giant turtle. Ratchet, who had known this all along, uses his mechanical castle to take control of the turtle, in order to use it, to take over the world. Now the Straw Hats have to stop not only Ratchet, but also the helpless turtle, from crashing into a nearby island.
田中真弓
as Monkey D. Luffy (voice)
中井和哉
as Roronoa Zoro (voice)
岡村明美
as Nami (voice)
山口勝平
as Usopp (voice)
平田広明
as Sanji (voice)
伊倉一恵
as Tony Tony Chopper (voice)
山口由里子
as Nico Robin (voice)
稲垣吾郎
as Dr. Rachet (voice)
加藤浩次
as General Maji (voice)
Keiichiro Yamamoto
as Colonel Honki (voice)
京田尚子
as Roba (voice)
青野武
as Gonzou (voice)
