Based on the Gilbert and Sullivan comic opera The Mikado, the plot is reset into contemporary Japan as a comic gangster story. The dialogue is largely rewritten, and several of the well known musical items are omitted. The music that remains is re-orchestrated into styles popular in the early 1960s, including the twist, and the Cha-Cha-Cha. Filmed entirely on a sound stage, stock footage was used to provide Japanese atmosphere between scenes. This footage looks like one of the many travelogues for which producer Baim is best known but according to Winner's autobiography this footage was specially shot. Winner credits the film's problems to the fact it was underfunded. No attempt appears to have been made to disguise the stage-bound filming. The colourful sparsely-dressed sets, not always tending towards realism, give the film a surreal quality.
The following music and styles appear in the film. Except for the ‘Mikado’s Song’, containing some topical lines, lyrics are unchanged. Although heavily re-orchestrated, the melodies were left essentially intact.
"The Sun and I" – instrumental twist used for the opening credits
"We are Gentlemen of Japan" – male chorus in a ‘Tijuana brass’ type setting
"Bellow of the Blast" – featured instrumental played in the style of a ‘strip’ tune
"Three Little Maids" – female trio, set as a Cha-Cha-Cha followed by a featured dance
"Overture extract" – a twist and used as incidental music
"The Sun and I" – female solo
"A Wandering Minstrel" – male solo in a crooner style
"Lord High Executioner" – chorus with a ‘Tijuana brass’ backing
"Finale Act 1" – extract set in a jazzy style and used as a short dance routine
"The Sun and I" – instrumental twist used as incidental music
"Here’s a Howdy do" – duet sung as a Cha-Cha-Cha
"A Wandering Minstrel" – instrumental small jazz combo arrangement used as incidental music
Hank, the son of American judge Herbert Mikado, refuses to marry Katie Shaw, whom his father wishes him to marry, and so joins the army. He is stationed in Japan where he falls in love with a Tokyo art student, Yum-Yum. However, her fiancé, Ko-Ko, an American gangster operating in Japan, is determined to keep Hank and Yum-Yum apart. Hank's father had also sentenced Ko-Ko's brother to prison.