There actually are a lot of Filipino workers in Japan, and Korea, but I do get that that's not really the point of your question...
I can't quite answer your question, but I can tell you from a reverse perspective -- that is, from being a Filipino growing up in multi-racial America, to moving to the Philippines, where almost everyone is the same race -- it was really, really weird. Whenever you see a crowd in America, whether it's on the street, in an athletic stadium, at a rally, etc, it always looks like a rainbow of colors, because of people's hair, eye and skin color. During my first month in the Philippines, I watched a concert or something on TV, and when they showed the audience in the stadium I was shocked at what the people looked like: It was nothing but a sea of brown faces, thousands of them, and every single one of them had black hair. My sister, like me, thought it was hilarious and remarked, "Look at all those Filipinos! Every person there is a Filipino!" To me instead of the normal "rainbow" I was used to seeing, it just looked like a sea of dirt.
Again, I myself am Filipino, but it was weird to see nothing but Filipinos everywhere I went. I got used to it after a few months, of course.