The woman known as 'Tokyo Rose' was American of Japanese descent and was a convicted traitor. Although Gerald Ford pardoned her in the 1970s, it still shows your statement to be untrue.
I am not sure how you can defend and pump the Imperial Japanese and their American descendants especially the Kibei. I mean why are you doing this? And to try and foist your idea that the Nisei were the most decorated?? What are you trying to accomplish?
I'll tell you what you are trying to do. You are doing what many of the Japanese have done since the conclusion of that conflict and that is defend the honor of the race. Honor is so important to Imperial Japanese loyalists that they have been in denial about the atrocities or attempted to equate them with other war atrocities, they have created a revisionist history and refused to apologize for the war crimes committed, and they try to obfuscate and even eliminate references to Japanese betrayal and to promote Japanese as something that they were not.
Unfortunately for you that history remembers. To this day the Japanese are hated by many survivors throughout Asia and the Pacific.
Tokyo Rose was in Japan, which is why the comment specifically stated Americans of Japanese descent in the United States.