Although there were good circumstantial reasons of timing and other factors that made Japan unwilling to sign onto the alliance Hitler was seeking with them in 1939, it is important to note that Hitler did pursue such an alliance and some Japanese at points in 37, 38 and 39 favored it.
So how can we make it come to fruition?
Justified or not, Hitler placed a lot of confidence in Japan's ability to distract his enemies, so if a deal were made, he probably would not offer an explicit non-aggression pact to the Soviets, or agree to Soviet territorial aggrandizement in Europe.