Germany has alliances with Italy, Japan, Romania, Hungary and Bulgaria; did they adapt their racial theory to promote the idea that these nations ethnic groups were superior to others? It seems hard to think that Nazis would include the Japanese and Slavic Bulgarians to their favoured races lists.
Hitler declared the Japanese "Honorary Aryans." In a speech he made (which I will take directly from Wikipedia because it's at hand, although I have a slightly different translation in my book),
"Pride in one's own race – and that does not imply contempt for other races – is also a normal and healthy sentiment. I have never regarded the Chinese or the Japanese as being inferior to ourselves. They belong to ancient civilizations, and I admit freely that their past history is superior to our own. They have the right to be proud of their past, just as we have the right to be proud of the civilization to which we belong. Indeed, I believe the more steadfast the Chinese and the Japanese remain in their pride of race, the easier I shall find it to get on with them."
Hitler wanted an ally in the Far East in preparation for his war against the Soviet Union. His two candidates were China and Japan. While actual Japanese help to the Germans was minimal at best during the course of WW2, he didn't want to diplomatically isolate himself. In fact, until the Sino-Japanese war broke out in earnest in 1937-1938, Hitler was still trying to be an ally to both China and Japan, as evidenced by Chinese soldiers wearing German helmets, using German rifles, trained by German advisers, and adopting a German doctrine.