I know this thread is a few months old but I didn't feel it was worth opening another one.
It seems like gaijin is a controversial word.
Broadcasting and publishing
The word gaijin is classified as racial discrimination (人種差別) and included on a common list of prohibited words used by Japanese broadcasters and publishers. The list recommends the use of gaikokujin instead. However, adherence to these lists is voluntary, and its contents are often criticized as excessively cautious (see kotobagari). Gaijin is not listed on the Broadcasting Code master list of prohibited words that all TV and radio broadcasters adhere to.
So I don't know which conclusion to come to seeing the use of it on here...
1. Is it not as offensive as it's made out to be?
2. Is it offensive but people on here use it anyway?
3. Is it like the "N" word in the sense that it is historically negative but generally acceptable among black people to say it to each other but offensive if someone else says it?
My teacher made it seem like this word should not be used and just expressed it as "no, no, no.. not very nice" and shaked his head. Although I can see that in a teaching institution the language they would want to teach would be more stiff (no slang).
I just want to know if the shirt I saw on cafepress that says "Kiss Me I'm Gaijin" would make the Japanese laugh for all the wrong reasons.