The title refers to the radioactive fallout which descended upon ruined city of Hiroshima after the dropping of the first atomic bomb. Young bride-to-be Yoshiko Tanaka has the misfortune to be visiting Hiroshima on the day of the explosion. Incredibly, she is unhurt; she returns to her own village, across the bay from Hiroshima.
Unfortunately, her townsmen have been profoundly affected by the black rain; over the next five years, the poison in their systems slowly but surely erodes their souls. In a tragic state of denial, Yoshiko's former friends insist that they can't be sick-it must be the girl who is bringing sickness to them.
Now a pariah, Yoshiko's life is shattered as surely as if the bomb had disintegrated her upon impact.
Director Shohei Imamaura, a onetime assistant to the great Ozu and the director of such Japanese classics as The Insect Woman and The Ballad of Narayama, never sensationalizes his material; the story is effective told in a muted, subdued fashion, allowing the horror to arise from the inner torment of the characters rather than being artificially imposed by camera trickery or shock cutting.
Based on a novel by Masuji Ibuse, the black-and-white Black Rain won the Japanese equivalent of the Academy Award, along with several other honors.