I Live in Fear (1955, Jp.) (aka Record of a Living Being, or Ikimono no kiroku)

In writer/director Akira Kurosawa's family drama - a tale of inter-generational rivalries during an age of atomic paranoia in the mid-1950s (a decade after the bombing of Hiroshima and Nagasaki):

• the opening credits sequence - with views of traffic at a busy Tokyo intersection, accompanied by theremin music
• the character of the lead protagonist: elderly, self-made, wealthy, eccentric and age-degenerating steel foundry owner Mr. Kiichi Nakajima (Toshiro Mifune), facing the debilitating, fear-stricken dread of nuclear weapons and radioactive fallout, and stubbornly determined to convince his reluctant, greedy, and entitled family members to emigrate to a farm in Brazil for safety's sake
• the sequence of the overly-anxious, increasingly mad industrialist Nakajima confusing bright flashes of lightning and thunder for a nuclear attack, ducking at imagined blasts, and panicking
• the continuing domestic-family arbitration case, led by a three-person tribunal (and arbitrator-counselor Dr. Harada (Takashi Shimura), a dentist), to rule on the overly-worried Nakajima's rationality and mental competency (and the fate of their inheritance) - and whether he could sell his foundry and home, and uproot his entire family to Brazil
• in the film's conclusion, Nakajima's desperate and irrational decision to destroy his assets (by burning down his factory, and unwittingly hurt his factory workers) to persuade his family - afterwards, he was committed and placed in an insane asylum, where he sat with his delusions while staring at the sun - (believing he had safely escaped from Earth and transported elsewhere) - in a chilling moment, he cried out as he pointed out the barred window at the rising sun: "It's burning! It's burning! The earth is at last burning away"
• the film's final juxtaposed, metaphoric shot of differing generations: Dr. Harada slowly descended the sloped corridor of the mental hospital after his visit, while Nakajima's mistress Asako Kuribayashi (Akemi Negishi), bearing her little boy on her back, walked up a stairway - they both passed each other without recognition

Passing By Each Other on Staircase