But I didn't think it was a racist remark? I thought it was just some harmless slang like "Uncle Tom" ?

Confused.org/youminge

Ummm, I have been dealing with the Japanese every day and I mean every day for the last 4 years. Brilliant, friendly, respectful people who have a very funny side when you get to know them. I don't find them inherently racist at all. But seeing as Bill has extensive experience of their culture I'll bow down to his knowledge.