In Nazi Germany certain people or people groups could be designated as "honorary Aryans." Amin al-Husseini was a Palestinian Mufti who was granted honorary Aryan status. Even in spite of Hitler's virulent antisemitism quite a few Jewish or partially Jewish friends and family members of Nazi party officials were given this title.These honorary Aryans weren't completely free from harassment but were generally spared.

Funnily enough, Japan wasn't even Hitler's first choice as an ally in East Asia. Until the Chinese were completely humiliated by the Japanese during the first few years of the Sino-Japanese War, Chiang Kai-Shek's nationalist government was preferred over the Japanese. Both Chinese and Japanese people were considered honorary Aryans despite the fact that in earlier years in the Third Reich, they were considered "untermenschen" and were subject to racially motivated crimes and harassment.

Before the German invasion of the Soviet Union, Turkic ethnic groups were considered sub-human. When the Nazi's wanted to foment anti-russian sentiment among ethnic Turks in the Soviet Union this policy was changed, and over the course of the war around 300,000 ethnic Turkic troops fought in the Wehrmacht as well as a myriad of other different ethnic groups that by modern standards would by no means be considered white.

You probably see what I'm getting at--Nazi racial policy could be as fluid as Adolf Hitler wanted and/or needed it to be. It was everything but scientific and almost completely arbitrary, subject to Hitler's whims. Honorary Aryan status was granted whenever it was politically, militarily, or economically convenient; and that's why Hitler sided with the Japanese--it was convenient. The Japanese and the Germans had common enemies in the Allies and the Soviet Union and Hitler was willing to compromise his racial beliefs for practical reasons. You can't really expect a nut like Hitler to really have any actual quantifiable reasoning behind their dogma.

Anyway, feel free to ask me any other questions you may have. I hope that answers your question