Long story short: Guy walking through a japan city and for some reason is rummaging through peoples garbage. He stumbles upon a suitcase full of black and white photos. he scoops it up and takes it home to see what they are. He figures out that he just found 700 pictures of Hiroshima taken a few days after the US dropped the bomb. A group of Japanese photographers were asked to go through the city and document the destruction. I guess shortly after the these pictures were taken publishing them was outlawed...so they sat in a suitcase in a basement and were recently discovered on the curb.
Here is the short story longer.