Here’s a story from the Economist:

In Japan people are typically considered Japanese only if they have two Japanese parents, speak fluent Japanese, look the part and “act Japanese” https://t.co/owyvIBsax7 — The Economist (@TheEconomist) February 9, 2019

Of course, on Planet Economist, the existence of a half-black, half Japanese tennis star means Japan should rethink thousands of years of successful ethnocentrism. They're not alone in the that belief, the New York Times thinks so too.

Steve Sailer put it this way:

The Japanese are a physically small race and have few famous athletes on the world stage. Japan has also been one of the few successful countries to staunchly resist the zeitgeist’s pressures to open the borders, especially to the world’s fastest growing racial group, blacks. But big corporations are working to undermine Japan’s resolve, using, for example, a giant half-black American girl tennis player as a wedge.

At 5' 11", Ms. Osaka is bigger than almost all Japanese females (and most Japanese men) as well as more self-disciplined than Serena Williams.

For more on Naomi Osaka, see:

The thing is, our "Japan Doesn't Want Immigrants" tag features pages and pages of items going back to 2002, when we posted Peter Brimelow's 1993 (!) article "Closed Door", written for Forbes, in which Peter said:

The recent political turmoil in Japan may lead to some fundamental changes. But immigration is not likely to be affected much, judging by Forbes' recent conversation with a Japanese consular official who wished to remain anonymous. FORBES: I'd like to know the procedures to follow to immigrate to Japan and obtain Japanese citizenship. ANONYMOUS JAPANESE OFFICIAL: [Complete surprise and astonishment] Why do you want to immigrate to Japan? ... There is no immigration to Japan. FORBES: No political refugees or asylum seekers? ANONYMOUS JAPANESE OFFICIAL: There might be three people a year who become Japanese [chuckles]. And even they don't stay long, they try to go elsewhere, like the U.S. He's not joking. Japanese entry statistics don't seem to recognize the concept of an immigrant, as opposed to a visitor.

How do the Japanese manage without diversity? Pretty well!