I consider myself generally knowledgeable about world history, and especially European history. And yet I constantly find out about stuff I've never heard of. Here's a good one:
In 1919, the Japanese delegation to the Paris peace conference proposed a racial equality clause to the Covenant of the League of Nations.
The equality of nations being a basic principle of the League of Nations, the High Contracting Parties agree to accord as soon as possible to all alien nationals of states, members of the League, equal and just treatment in every respect making no distinction, either in law or in fact, on account of their race or nationality.
This basically caused Britain and Australia to go completely batshit. And Woodrow Wilson needed the support of Southern Democrats to ratify the treaty so he could not support the racial equality clause. The funny thing is that when the Japanese proposed this, they had not even considered that it would apply universally. In their head, their only beef was that Japanese were seen as inferior. As a matter of fact, the Japanese considered themselves superior to the Koreans and the Chinese, not to mention the dark skinned races.
This was quite a circus. The matter was brought to a vote and 11 countries out of 17 voted yes to the racial equality clause, the rest abstaining. Yet Wilson overturned the vote stating that he needed a unanimous yes vote to approve it.
As an aside, the Japanese were quite a wily bunch - they used the "Asia for Asians" campaign to agitate various European colonies in Asia to drive out the white colonists. However, the Japanese turned out to be as bad or worse once they filled the vacuum left by the Europeans.
As another aside, even as the Nazis came to power, the Japanese refused to exile Jewish refugees in lands occupied by Japan, but this was purely a calculation of economic and political opportunism as the Japanese believed they could benefit from the money-making abilities of the Jews.
All this can be found in detail in Wikipedia