JOHN YANG:

Among the thousands killed at Hiroshima were 12 American prisoners of war, the crew of three planes that were shot down on Hiroshima area.

Today, President Obama noted their deaths, as well as the quiet, diligent, four-decades-long effort of one man, Shigeaki Mori, a survivor of the bombing, who wanted to memorialize the 12 Americans. Mori attended Mr. Obama's speech, and the two men embraced.

Now a new film called "Paper Lanterns" charts Mori's quest as he sought permission from two of the families of the 12 POWs to register their names for a memorial.

Here is a clip from the film, where Ralph Neal of Kentucky and Susan Brissette Archinski of Massachusetts read the letters Mori sent them seven years ago about their uncles.

SUSAN BRISSETTE ARCHINSKI, Niece of U.S. Veteran: "Dear Mrs. Susan Brissette Archinski."

RALPH NEAL, Nephew of U.S. Veteran: "Dear Mr. Ralph Neal, I hope this letter finds you well. My name is Shigeaki Mori, a 72-year-old A-bomb survivor and a historian living in Hiroshima, Japan.

"For a long time, I have been reading about American soldiers killed by the atomic bomb. I have erected a memorial dedicated to their unfortunate death. The 64th anniversary of the A-bomb of the city is coming around soon. On this day every year, memorial services are held in the Peace Park under the auspices of the Hiroshima mayor.

"A stone room in the center of the cenotaph, a main structure in the center of the park, contains a list of the domestic and overseas victims of the A-bomb, including those American soldiers who happened to be in the city when the bomb exploded.