According to the 2005 American Community Survey, Chicago has 128,650 people of Asian Decent. I cannot find a breakdown of Asian Ethnicities in Chicago, but I would imagine a large large majority of those 128k are Chinese, Korean and Filipino. Census 2000 shows that there are approximately 7,411 Japanese Americans living in Chicago, and 17,398 in Cook County. San Diego on the other hand has 190,893 people of Asian Decent in its city. According to a 2005 poll, San Diego COUNTY (population of about 2.9 million, roughly the size of Chicago give or take 150,000) has around 20,534 Japanese Americans living in their county. I guess thats a pretty sizable difference, as a much smaller metro (2.9 mil vs. about 9 million) has 3,000 more Japanese people in it. But of course comparing the 2 metros doesn't take into account that LA is about 1.5-2 hours north of SD and has a pretty big Japanese population.