Yes, Japan's racist immigration policies mean that there are very few foreigners living in Japan. But I wasn't talking about foreign nationals. I was talking about within the Japanese. The Ainu are obviously a distinct race and culture. Okinawans aren't that genetically dissimilar, but their culture and language certainly are. Add ethnic Koreans, Chinese, and Brazilians, and the burakumin—who are discriminated against as much as anyone—and you're already at some 4-6 million people. Add other immigrants and minorities, and that's a not-insignificant chunk of the population.

Furthermore, Japan wasn't unified until around 1600. Like most of Europe, it was a cluster of warring nation-states. And yet while European countries still, to this day, have great variations within their relatively small areas and populations, a nation of 120 million people has somehow managed to unify so completely in 400 years that there's no substantive difference in its people? I don't buy it. And if you just travel to Kyushu or Hokkaido from the mainland, that difference is obvious. It's like the UK in that respect. Even if you only look at British whites, despite a shared common culture there are deep and lasting divisions between the different areas of the nation.

Now, Japanese homogeneity is to a degree, a self-fulfilling prophecy. By creating a 'standard' Japanese and perpetuating the idea that the Japanese are all the same, the people themselves have bought into it to a large degree. Still, the best you can really say is that Japan is a bit more homogenous than other places, but there are places like Iceland, some African countries, etc. that are even more homogeneous, depending on what metrics you use.

So... racism. Most racism against blacks in the U.S. these days is pretty much the same as racism towards foreigners in Japan. So can we say that there's no racism towards blacks in the U.S.? People who cross the street to avoid black people aren't any different than Japanese people who avoid Westerners, right?

Even if you discount that situation, it goes much further than that. Again, talk to some zainichi Koreans or half-Japanese half-Western kids about what they've had to deal with. Discrimination in employment, bullying in school, discrimination in government policies, and the constant reminders that despite the fact that they were born and raised in Japan, they will never be 'true' Japanese.

TofuTofu guessed he was white, because whites from predominantly white countries don't have to deal with the sort of subtle racism they experience in Japan, and thus are surprised to encounter it. People who have lived as minorities are used to it. (Yes, white people also love to feel victimized.)

Avoiding someone because they look foreign is racism, pure and simple. Treating anyone differently because of their race is, by definition, racism. That's all there is to it.

Yes, there are degrees of racism. It is not a black and white issue. No, it is not the worst sort of racism by a long shot. (I myself have experienced everything from the aforementioned condescension and avoidance to being told to go back to my country and suckerpunched by a chinpira.) But it is still racism!

If you are going to continue arguing that the OP's experience does not reveal a pattern of racism, you are either being intentionally dense or you simply don't understand the meaning of the word.

It's a complex issue and both whiny expats and Japan apologists (a category you are skating dangerously close to, my friend) do reality a disservice with this sort of reductionism.