The historical documentary,
Proof of Loyalty
, is produced by Stourwater Pictures.

Stourwater Pictures is an award-winning documentary production company that specializes in historical documentaries on Pacific Rim and Pacific Northwest subjects. Discover more about us and explore our other films at www.stourwater.com.

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Tyrone Beason of the Seattle Times has written a discerning and perceptive piece about Kazuo Yamane and the film, published on Veterans Day. We include a few paragraphs below. The entire review can be seen here.

"Immigrant Japanese like Kazuo Yamane’s parents, a generation known as Issei, weren’t made eligible for U.S. citizenship until 1952 because of decades-old discriminatory policies aimed at excluding and marginalizing foreign-born Asians.

"Still, they raised their U.S.-born children to love this country.

"In a community that was often viewed as a threat, America found some of its greatest defenders."


The Association for Asian Studies has included an enthusiastic review in their publication Education About Asia. We include a few paragraphs below. The entire review can be seen here.

"Proof of Loyalty is the story of Kazuo Yamane, a Japanese-American born and raised in Hawai`i, who made immeasurable contributions to the successful Allied war efforts and the story of the “Nisei”— those second-generation Japanese-Americans who served America so well during the war….

"The film is better organized than many documentaries, has superb narration, contains remarkable quality for war footage, and richly blends the stories of Yamane’s youth with his superior wartime service and numerous high-quality photos of family and friends. This story of unparalleled loyalty was set aside and almost forgotten, as Japanese-Americans returned from their military service to Hawai`i. Yet as the stories emerged in the 1990s, the Nisei were finally recognized by Congress, and Yamane was awarded the Legion of Merit in 1997.

"The documentary contains a great lesson to these difficult times, when bigotry and bias are on the rise: diversity is what has made America great."


We are grateful to Richard Propes, The Independent Critic, for his very positive review. We include a few paragraphs below. The entire review can be seen here.

"If you see this film, and you should, you'll understand completely why audiences rave about it. 

"Running just shy of an hour, Proof of Loyalty tells its story quickly and doesn't waste time with any unnecessary filler. Fortunately, there's also no gimmicks here or unnecessary histrionics. There's simply the story of Yamane, the Nisei soldiers, and their unwavering loyalty despite experiencing tremendous discrimination from an American public that tended to regard those of Japanese descent as "the enemy" no matter how passionate their loyalty. 

"In this time, especially, with many immigrants having their military service questioned and even ended, Proof of Loyalty is a powerful reminder that America operates best, even during times of war, when it embraces its diversity."


"Brilliantly mixing archival footage and intelligent interviews, Lucy Ostrander and Don Sellers tell the story of Kazuo Yamane and his fellow Japanese Americans who proved their patriotism through their military exploits amid the most trying circumstances during World War II."


"How far would we be willing to go to demonstrate loyalty to this country, even if our own families faced discrimination - & we had too? The little known story of Kazuo Yamane conveys how one man’s actions & belief in his country were significant in turning the tide of World War II. More than that, it depicts how those least trusted during the war - because they looked like the enemy - became invaluable to our war effort. The rich archival images, context given by historians and veterans, and the haunting music complement this vivid story highlighting Kazuo Yamane but also telling of Japanese Americans’ critical contributions during World War II. More than anything, these events from the past should make us ponder how we address race and ancestry today."


"Proof of Loyalty is a powerful documentary of the vital World War II role of the Nisei soldiers of Hawaii in winning the war in the Pacific and in Europe and in doing so establishing the unquestioned loyalty of Japanese Americans which then empowered this ethnic group to transform and democratize Hawaii in the postwar era.  While providing the overall history of Japanese Americans in prewar Hawaii and intertwining the story of other Nisei soldiers, the voice and remarkable experiences of Kazuo Yamane are at the center of this film. Because of his unique linguistic and military knowledge gained from studying in prewar Japan he was able to identify and translate critical information from captured Japanese documents that guided the U.S. strategic bombing campaign against Japanese military industrial targets, proving the value and loyalty of a discriminated racialized minority whose government ultimately entrusted with vital national security tasks. It is a timely message of the power of diversity."


"Proof of Loyalty, the story of elite translator Kazuo Yamane, is a superb lens to view the WWII contribution of Japanese American soldiers from Hawaii. Through stunning, little-known footage and precise narration, Proof of Loyalty captures the sad irony that those we discriminate against may be among our most able, tireless, and faithful. A meticulous, powerful, and all too timely film."


"A combination of great archival photos, good writing, expert commentary and skillfully used narration and music makes this film a wonderful resource for anyone interested in Japanese Americans in Hawaii, and especially the story of their contribution to the United States’ efforts in World War II. I was particularly impressed by the deep background the documentary provided, telling the story of how Japanese immigrants originally came to Hawaii, eventually becoming the parents of Hawaiian Nisei soldiers who played critical roles in the War. It’s a fascinating story told in a very engaging way."



"A remarkable true tale of a Nisei soldier dramatically affecting the positive outcome of World War II. Don't miss it."


"The story of Japanese-Americans in Hawaii is a unique one, and as with any unique story, it is difficult to tell in a way that is both comprehensive and personal. But PROOF OF LOYALTY manages to do just that, using the inspiring story of World War II hero Kazuo Yamane as a window into the Japanese-American experience in Hawaii.
During World War II, the United States interned over 100,000 Japanese-Americans in camps. But of the over 150,000 Japanese-Americans in Hawaii, less than 2,000 were interned. In fact, a select group of a few hundred Japanese-American men in Hawaii were recruited to translate Japanese for the American Army. These troops, known as the 100th Infantry Battalion, were seen as an experiment that would prove whether any Japanese-Americans could truly be trusted to be loyal to the United States. These men proved not only to be loyal, but also instrumental to winning the war.

Men like Kazuo Yamane are a reminder of what truly makes America great. Japanese-Americans had no obligation to love the United States during World War II. The discrimination they faced is a stain on American history, revealing the darkest, ugliest impulses of American society. Yet the brave Japanese-American soldiers we see in PROOF OF LOYALTY risked everything for their country and ended up saving countless lives through their translation work. They prove that America’s strength comes not from military might, but from diversity. This film may be about men from decades past, but it couldn’t be more relevant."