Upvote:3
I think more than anything the reasons were geopolitical expediency.
For example Germany and Japan began rapprochement when they signed the Anti-Comintern Pact in 1936. At this time Hitler was looking for a reliable partner to contain the Soviet Union - and when the Chinese nationalists signed the Sino-Soviet Non-Aggression Pact, Hitler concluded that Japan would be a more reliable partner against the Soviets in East Asia. This was despite the fact that by 1938 Japan had not decided to expand north against the Soviets.
The Japanese also felt driven closer to Germany as the United States placed greater export controls on the Japanese to deter further territorial expansion.
It is also true that the Prussians and later Germans played a part in the industrialisation of Japan and the drafting of its Constitution.
To quote wikipedia, From the signing of the Anti-Comintern Pact to the Tripartite Pact in 1940
Relations between Germany and Japan were driven by mutual self-interest, underpinned by the shared militarist, expansionist and nationalistic ideologies of their respective governments.[44]
This statement probably sums up the entire issue in a nutshell.
Upvote:4
In the 19th century, Japan sent out missions to learn different things from different industrialized powers. They were in a position to pick and choose their role models.
I wonder if the Army faction in WWII was more predisposed to ally with Germany than the Navy faction. You might note that Japan allied with the Allies in WWI.
Another factor would be antagonism to Russia. They allied with the enemy of their enemy.