[2] The film is about an elderly Japanese factory owner so terrified of the prospect of a nuclear attack that he becomes determined to move his entire extended family to what he imagines is the safety of a farm in Brazil.
[3] Kiichi Nakajima (Toshiro Mifune) is an elderly foundry owner who is convinced he and his loved ones will all be killed in an imminent nuclear war if they stay in Japan, so he resolves to move them to perceived safety in Brazil.
Kiichi's three oldest children convince his wife to try to have him ruled incompetent in order to keep him from wasting their inheritance on his plan, and they bring him before a three-man arbitration panel that includes Dr. Harada (Takashi Shimura).
He wonders aloud whether it may be wrong to rule someone incompetent simply for being more worried than the average citizen, but the panel eventually decides that Kiichi's irrational behavior justifies removing his ability to make the financial decisions for his family by himself.
While waiting to be shown to his room, Harada talks with a psychologist, who remarks that he has found Kiichi's case particularly troubling personally, since it has made him wonder whether it may be more insane to ignore the nuclear threat than it is to take it too seriously.