Black Rain

A key theme in Black Rain is the unknowable suffering endured by the people of Hiroshima. Not only are they victims of the world's first atomic bomb, but they also have no way to comprehend what has happened to them. The terrifying new technology is so little understood by the characters that they cannot understand why they are becoming sick. To them, the reality of radiation poisoning is a complete mystery. They remain on the bomb site and wander through the ruins of the city. They eat food contaminated by the radiation and wash themselves in water that has been directly affected by the bomb. To a modern audience with a better understanding of the effects of radiation, and to Shigematsu reflecting on the events in his diary, there is a sense of dramatic irony. The audience and the diary transcriber understand events and phenomena the characters in the story do not. The days immediately after the bombing are made even worse by the victims not knowing how or why they are suffering. The vacuum of information causes more suffering as people sort through the ruins of the burning city, desperate to understand what is happening to them but unable to do so.

The invisibility of the radiation plays into the theme of unknowable suffering. Atomic technology is incomprehensible to the characters in 1945. They do not understand this new type of technology, nor do they understand how it has been weaponized against them. The radiation that causes so many problems is invisible to the naked eye; a ghostly force intensifies the suffering of the victims in a way they cannot immediately comprehend. Furthermore, the victims do not need to make physical contact with anything to be infected by radiation. Instead, the ambient level of suffering is increased in ways they do not understand. The air, the water, and everything else is turned into a threat that affects people for years after. This unknowable suffering can even strike many years later, as it does with Yasuko. Her life is ruined, and her health deteriorates years after she comes into contact with the invisible radiation. She could not ever know or expect that the radiation would cause such problems, but her suffering is driven by an unknowable new technology, the effects of which could not have been predicted or expected by the characters.

The source of the atomic bomb is the United States Army. However, the United States have no real presence in the book. They are ostensibly the enemy, but the characters never meet or interact with an American beyond the occasional airplane seen flying overhead. The Americans are presented as a force of nature that cannot be reckoned with. This creates a distinction between the knowable and the unknowable. For Shigematsu, the Japanese institutions such as the state and the army are knowable. He understands these institutions, and he understands the suffering they cause through their collapse or through their ineffectiveness. The Americans in the novel are defined by their absence: they are a hollow void, something like a hurricane or an earthquake. The atomic bomb may be the product of American ingenuity, but the problems it causes are seen through the knowable world of Japanese institutions. To Shigematsu, these institutions can be criticized and blamed while the unknowable source of the bomb exists beyond the realm of comprehension.