Please use the term "Honorary Aryan" rather than "East Aryan", OP. Hitler nor anyone belonging to the Nazi party never used latter to refer to them. See:
https://en.wikipedia.org/wiki/Honorary_Aryan (Kikepedia, I know, but there's nothing non-factual about this article in specific based on my research).
Also, I think most of that is probably associated with losing the war and becoming a puppet state of America, since we can see the similar effects to that in Germany as well. The only difference is that Japan got to keep some of it's nationalism and racial pride, Germans started to hate themselves and their nation due to so much brainwashing regarding the Nazis and the Holocaust.