In 1876, young Takanosuke Arashi is sent by the Edo government to deliver a top-secret message to the United States of America. When his ship is waylaid by pirates, Takanosuke is cast adrift with an eclectic group of passengers, including a dog with four names, and part of a treasure map. Then begins an adventure that will take Rakanosuke around the world, from the wild-west, to old Morocco, to Baghdad. Who will get their hands on Napoleon's treasure first?