While trying to enjoy a simple Japanese meal, Goemon has been arrested and thrown into prison! This is all part of a scheme to use Goemon as leverage against Lupin. An arm to a mermaid statue is in the wreckage of the Santa Maria; if Lupin can retrieve it, Goemon will be freed as payment for Lupin's services. Can Lupin outwit everyone and resist the amorous advances of a dolphin?