I was in Korea with a german friend, visiting a templein Seoul. We arrivedto the temple pretty early and the next tour in english was around midday. My friend, feeling confident in my japanese, decided to take the japanese tour instead...

We ended up in a group of almost 100 Japansese, not to mention we were the only gaijin, everyone stared at us!
While queueing, I heard a few comments from a lady in her 50s, standing behind us. She siad: aahah look at these stupid gaijini (baka gaijin), they`re taking the Japanese tour and won`t understand a word! How can they be so stupid..(sonna ni bakayaro)

I couldn`t contain myself by saying something! I broke into the conversation and told her: look, I speak Japanese I`m going to translate for my friend. You`ve been very unrespectful and noisy (shitsurei and urusai) and you should apologise for what you siad!

She realised she had put her foot in her mouth and started praising my japanese, " oh your pronounciation is so good", "oh you should come and visit me in Tokyo"...and so on!

I think some of them don`t really mean anything when use the word gaijin. But I have to say that many people use it as a derogatory word to address the foreigner as "weird creatures coming from outside"!