Generalizations are useful, as long as we always keep in mind that there are always exception to the general rule.
All agents and experienced punters know that generally speaking Japanese girls give great service, Malay/Sing give great service, Chinese girls are around 50/50, and Korean girls don't give great service.
Generally speaking of course!
Most of you on this forum who have been punting for a while could easily give many examples of girls who are the exception to these generalizations.
Anyway to get back to the point. I am sure Ginza would hire a Korean girl who was friendly and gave great service.
It's not about nationality - it's about looks, attitude and service.