The movie begins in Hiroshima on Aug. 6, 1945 with images of everyday life: a young woman traveling, a running dog, people boarding a train. The girl is Yasuko, making her way out of Hiroshima, and her uncle, Shigematsu, is on the train when the atomic bomb hits. Except for fire, rubble and corpses, the blast leaves behind a city that, as characters repeat throughout the movie, has all but disappeared.
Yasuko suffers no injuries but is hit by the black rain, the fallout from the mushroom cloud containing dust, soot and radioactive materials. She finds Shigematsu and her aunt, Shigeko, and the three, weak and horrified, must find their way across the city to safety.
The scenes of Hiroshima are short but gruesome: a woman grieves in a corner, clutching her dead child; a boy, skin dripping from his bones, pleads with his brother to recognize him; bodies burned in strange positions float down the river like lanterns lighting the way to the afterlife.
The film's focus is not on that day in Hiroshima, however, but on the bomb's after-effects, both physical and psychological. The story jumps ahead five years to a village outside the city where Yasuko, Shigematsu and Shigeko try to carry on normal lives despite their fear of the radiation sickness which threatens to strike at any time.
Attempting to resume everyday customs and traditions, Shigematsu and Shigeko preoccupy themselves with finding a husband for Yasuko, who is well into marrying
age. She has many suitors but her certificate of health is unconvincing, and proposals fall through as an unknown villager spreads rumors about her health.
Shigeko begins to experience the symptoms that Shigematsu has shown for years, but both continue to insist that Yasuko was unharmed by the bomb. Yasuko, however, acknowledges that the black rain was poisonous; it is perhaps only after she starts to lose her hair in clumps that Shigematsu and Shigeko accept the truth.
The family cannot escape death, and as they watch the effects of the bomb catch up with neighbors and friends, we watch funeral processions and funerals pyre multiply.
The bomb brought not only death, but prejudices and guilt. Villagers accuse the sick of being lazy and spread rumors about Yasuko's heath to prevent her from marrying. Shigematsu blames himself for bringing Yasuko into Hiroshima and being unable to find her a husband. Shigeko attributes her illness to jealousy, while Yasuko believes her illness makes her unworthy of her suitors.
The film ends with Yasuko's death and Shigematsu's vain plea for a rainbow ñ a poignant prayer in a black and white color palate. "Black Rain" is far from a diatribe against America ñ surprisingly, there are only one or two references to the U.S. in the movie ñ but looks at the long-term effects of the atomic bomb and the Japanese response, successfully telling the story of one hibakusha family's struggle in a way that is moving without being melodramatic or overly-sentimental.