In his first film in two years, James Cagney stars as Nick Condon, the American editor of a pre-WW2 Tokyo newspaper. When two of his best friends are horribly murdered, Condon suspects that the "peaceful" Japanese military government is up to no good. He dedicates himself to getting his hands on the "Tanka Plan," a Japanese blueprint for conquering the world, and bringing this document to the attention of the Free World. As a result, he is targeted for persecution by the corrupt Tokyo police and betrayed by a traitorous fellow journalist. On a pleasanter note, Condon makes the acquaintance of half-Chinese Iris Hilliard (Sylvia Sidney), who agrees to help him foil the Japanese High Command. As was customary in wartime films, virtually all the Japanese characters in Blood on the Sun are played by Chinese, Korean, and Caucasian actors; for example, Robert Armstrong is cast as Colonel Tojo, while Premiere Tenaka is enacted by John Emery.