Jerry Lewis plays Gilbert "The Great" Wooley, a down-on-his-luck magician who brings his act to entertain USO troops in Japan, but instead causes chaos and befuddles everyone around him, including an orphan boy named Mitsuo Watanabe that he becomes attached to. The film follows their unlikely friendship as they navigate the cultural differences between America and Japan, with Gilbert struggling to balance his entertainment career with his growing feelings for Mitsuo's aunt Kimi. In the end, Gilbert decides to stay in Japan and find success as a magician, while Mitsuo returns home but finds a new life in America thanks to Gilbert's efforts.