Is it true that the Japanese do not like gaijin in their country?

Question:

What if they are at least proficient in Japanese?

Answer:

The question is subjective.

I would say the VAST majority of Japanese do not care about the issue.

It is only a small MINORITY of people that keep the fires burning. I'm not sure what country you are from, but I would argue it is the same in your country as well. For example, in America, a country built on immigration, you have hate groups like the KKK and White Supremacist and other groups that do not like foreigeners, obviously these groups do not speak for the whole of America, but because they are a miniority and high profile, someone who doesn't live in America might think otherwise if they saw videos of these people on the internet, etc.