[GoNative]

I can understand misunderstandings due to lack of language skills but as I said before I have heard numerous things said by Japanese people that we Westerners back in our home countries would undoubtedly consider racist but they would be surprised to think we thought of their comments that way.
But their comments were based on race and are most definitely racist by it's very definition. They may not be overly malicious in their intent and their comments may be based just on stereotypes and ignorance but in my book that's not an excuse for racism it's just a reason for it. An understanding of Japanese culture can make it more understandable why they don't perceive some of their comments as racist but doesn't take away the fact that they are. I don't really believe that there are cultural nuances to racism. Racism needs no great understanding of languages or cultures to be recognisable as far as I'm concerned. Knowledge of language and culture can help you understand the reasons behind the racism though. As I said earlier racism here is on the whole pretty benign but I think it plays a significant role as to why Japan has steadfastly remained a monoculture society.