天晴爛漫！

優秀だが社会的に無能な技師・空野天晴と、抜け目ないが臆病な侍・一色小雨は、ある事故により日本からアメリカへ船で漂流することになる。After a certain mishap, the brilliant but socially inept engineer Apare Sorano and the shrewd but cowardly samurai Kosame Isshiki find themselves drifting on a boat from Japan to America. Broke, the two decide to compete in the Trans-America Wild Race to win the prize and return to Japan. The two battle crazy rivals, outlaws, and the great outdoors itself as they race through the wild West from the starting line in Los Angeles to the finish line in New York - in the steam-powered car they built.