After the Going Merry narrowly escapes being hit by a "sea train", the crew meets an old woman, Kokoro, and her granddaughter, Chimney. Kokoro gives Luffy a map to Water Seven. Luffy, Nami, and Usopp buy boats driven by sea monsters called "yagara".

Franky has a painful encounter with monster Chopper, and Nami gets scrubbed too clean to fight! Meanwhile, Spandam accidentally invokes the deadly Buster Call!