A very homogeneous country like Japan (I could speak for that only, being a current resident), is generally inure to the culture of people around the world. Foreigners don't stick around long because they are like the thumb sticking out. One feels left out if not thick skinned enough.

In US, I always felt at home. There were people just like me - eating similar food, sharing different festivities, of same socioeconomic strata etc. Eventually inclusivity & diversity retains immigration. US (& UK as well) does better than most other developed countries