I thought it was common knowledge that Japanese keep foreigners at a distance? Reminds me of a story a good firned told me couple months back when he was visiting Osaka. At a computer shop discussing a flyer / specs sheet / something that was on a piece of paper in English. The shop owner would only talk in Japanese while pretending he didn't speak English, all the while pointing at various places on the English document it was obvious he could read the English without problem.
Just wasn't willing to speak English with a foreign white guy. I thought this type of attitude was common knowledge though? ANyway, doesn't surprise me at all many host bars in Japan have a no foreigner policy as that's just how the Japanese culture works, or at least that's what I've always assumed. / heard..