The US atomic bombing of Hiroshima killed tens of thousands of people, including a group of American prisoners of war. Few people know about their deaths, but Shigeaki Mori has been trying to change that.
Mori is a Japanese atomic bomb survivor, and he's the focus of a new documentary telling one of the lesser known stories of World War 2.
He met with the families of POWs who died when the US bombed Hiroshima. That moment -- which was years in the making -- is one of the scenes in "Paper Lanterns."
Mori was only 8 years old at the time of the bombing. But he has devoted much of his adult life to piecing together what happened to 12 American POWs.
The documentary's American director, Barry Frechette, says when he learned what Mori was doing, he had to know why.
"Well, why would you help these people, because they're the ones that dropped the bomb in the city, even though they didn't but they were part of the country that did," Frechette said. "Your gut reaction is 'No, I wouldn't help them,' and that's why I think Mr. Mori's story is so important."
The film shows Mori digging through documents and sending countless letters to the US to track down the families of the POWs.
Mori says when he first learned about them in the 70s, he was shocked they were not recognized as victims. He felt he needed to speak for them. And he wanted to tell their families about their deaths.
"When I finally got in touch with some of the family members, I remember that 3 of the letters I received from them were smeared with tears. I realized what a difficult time they had been going through," Mori says.
About 200 people attended a screening of the film in Tokyo on Tuesday.
"It's a very heavy feeling after the movie -- a very important topic," said one female audience member after the event.
For Mori, seeing his efforts on screen was emotional.
"I struggled through a difficult period while doing extensive research. The movie moved me to tears as it brought back those memories of my years of work," he said. "I would like to think that the work I did has historical significance."
The film is scheduled to also be shown in the United States. Frechette says he hopes people in his country will watch it and think about the tragedies that nuclear weapons can cause.
"I think what this story, at least what we're tried to tell, is the importance of compassion and humanity and seventy years later looking back and understanding what happened, and not forgetting it so it doesn't happen again," Frechette says.