The head of a large family, a wealthy industrialist, tries to persuade his family, his mistresses and their children, to emigrate to Brazil, where he thinks they will be safe from atomic extinction. The family, loath to leave their wealth behind, appeal to the Tokyo Family Court to have the man certified incompetent. He, however, persists that they all face annihilation, and burns his factory down to remove any financial ties that might hold the family to Japan. But his act renders his workers jobless, and the realisation of this drives him over the edge of sanity.

I Live in Fear was made in the year following the Russian, American and British nuclear bomb experiments, and the film expresses the misgivings Kurosawa and his co-workers shared with the people of Japan about the safety of mankind.