When Japanese actor Koichi Yamadera appeared on the popular variety show Monomane Battle in 2009 to perform the classic "What a Wonderful World," it was likely meant as a tribute to the American jazz tradition that still has a small, dedicated following in Japan. Yamadera, in apparent affection for the jazz master Louis Armstrong who popularized the song, did something that would have elicited gasps in the US but raised only polite applause from his totally unfazed Japanese audience. He put on full, unironic blackface:

It wasn't just him: Japanese singers imitating African-American performers have done this often. Baye McNeil, a black American writer who has lived in Japan for a decade, told me he found the blackface appalling — but didn't think it was worth wasting too much time on in a country he loves, despite suffering from routine racism.

"These singers were some old guys doing niche music and weren't that terribly popular, so it wasn't like they were in my face all the time," McNeil told me.

But McNeil lost his patience last month when members of a popular mainstream Japanese group posed for the promotional photo that appears at the top of this page. In it, the members of girl band Momoiro Clover Z grin in full blackface alongside old crooners Rats & Star, who have been performing in paint since the 1980s. The two bands were set to appear together on Fuji TV, a major network.

It was Black History Month, and McNeil had had enough. He was not going to let prominent young pop stars pass what he called the "baton of ignorance" to Japan’s next generation on national television.

He organized a petition on Change.org to get Fuji TV to drop the segment. Combined with an avalanche of tweets hashtagged #StopBlackfaceJapan, it worked: the show "Music Fair" aired on March 7 without the blackface performance.

But as McNeil knows all too well, this episode was only part of a much larger problem with race in Japan, a problem that cannot be quickly fixed with a petition. To Americans, and indeed most people, it’s pretty obvious that blackface is extremely racist. How could the Japanese, as well-educated as they often are, tolerate this practice? The answer goes way beyond mere ignorance of blackface's ugly history, to a powerful national belief in Japan's ethnic purity that leaves the country incapable of dealing with its race issues.

Japan's race problem

Japan's problem with racism is well-established. A 2005 report by a UN special rapporteur described "profound" racism in the country, much of it aimed at people from former Japanese colonial holdings in China and Korea.

In 2013, extremist nationalists led a series of anti-Korean protests; they threatened to flatten Tokyo’s Koreatown and build a gas chamber in its place. Japan is one of the few democracies without hate-speech laws, so little was done to stop this. Anti-racists staged counter-demos, and an extremist group has since been forced to pay compensation, but the national government has done stunningly little to prohibit racist hate speech, particularly given Japan's recent history of fascism.

"The blackface thing is emblematic of a larger problem of Japanese politics and civil society in which diversity is not recognized, or cultivated, or respected," said Kyle Cleveland, associate professor of sociology at Temple University’s Tokyo campus, who lectures on race.

This skepticism of diversity is all the more surprising given that Japan is a center of global tourism and trade, where foreigners are a common sight and foreign culture is commonly consumed. To understand why this is, you need to understand the powerful role that ethnic homogeneity — the idea of Japan as a nation of one blood — plays in its national identity.

Japan sees itself as homogeneous, even if it isn't

Japanese people tend to think of themselves as a being a single ethnicity (tan’itsu minzoku). The country is amazingly homogenous compared with many other developed nations; it's one of the least ethnically diverse countries on Earth, counting more than 98 percent of the population as Japanese nationals.

That sense of homogeneity has fed a series of cultural norms that encourage insularity. For example, the concept of uchi soto — of dividing "inside" from "outside" — governs behavior in all kinds of ways. Foreigners are most definitely "outside"; the word for foreigner, gaijin, literally means "outside person."

Japan has a complicated relationship with foreigners that can swing from fascination to bafflement to disdain — depending, in part, on where you are from.

"In general, Japan has a lot of admiration for Europe and more ambivalence toward the United States because of the wartime experience," said Cleveland. At the same time, "They tend to view themselves as superior compared with other Asians."

the idea of the nation as racially distinct and homogeneous remained deeply ingrained

Historians have long examined how Japan’s unique history could have shaped its complicated views about foreigners. In 1639, the country’s ruling Tokugawa shogunate made the momentous decision to cut off Japan from the rest of the world; except for limited trade, it stayed that way for another two centuries. Ordinary Japanese were forbidden from traveling abroad; foreigners became a source of endless fascination.

"There’s a whole discourse on what’s called the Galapagos effect — that Japan, having been isolated from foreign influence, developed its own kind of insular norms and values," Cleveland said.

Long after Japan reconnected with the rest of the world in 1853, the idea of the nation as racially distinct and homogeneous remained deeply ingrained. That manifested in its most extreme form during the country's imperial era, when the fascist government promoted a race-based, and extremely racist, official state ideology. This ended with Imperial Japan's defeat in World War II, but the underlying sense of Japan's identity as rooted in racial purity has, to some degree, remained.

In fact, Japan is home to various minorities, including Koreans, Brazilian Japanese, and a small indigenous Ainu community. But most Japanese continue to think of themselves as ethnically unified, and that’s key to understanding why racism remains pervasive in a country that otherwise seems so modern.

Simply put, if the general consensus in Japan is that the country is largely homogeneous, it just doesn’t need to have a big conversation about race. Issues that most other societies are forced to discuss can go totally ignored in Japan. Without that national conversation, lots of well-meaning people can end up holding ideas that have been widely rejected elsewhere.

Blackface in Japan is justified as "appreciation"

On the same topic, ever hear of the "b-style" thing in Japan? pic.twitter.com/q62izSJDn5 — Luke James (@lukejamesbgn) September 16, 2014

Japan’s insider/outsider mentality can lend itself to crude stereotyping of foreigners. And that’s not just black people — check out this ad for Japanese airline ANA featuring actors in "whiteface," complete with stick-on big noses.

The intent is not necessarily malicious. In fact, the use of blackface by Japanese musicians is often explained as a show of earnest appreciation for their favorite African-American legends. This anecdote from McNeil’s column in the Japan Times provides a glimpse into that common defense:

The other day, I showed a video of these Rats & Star guys to a Japanese co-worker of mine and, without giving him any clue why I had made him watch it, asked what he thought of it. "They want to be like black people," he said, grinning. "They love black people."

The idea of "appreciative" blackface is one that has appeared again in Japan more recently. "B-stylers," part of the small local hip-hop scene, are a niche youth subculture whose members seek to show their love of all things black — or their idea of blackness, anyway — by trying to look black, tanning themselves as dark as possible.

Both B-stylers and the aging blackface crooners are glaring examples of cultural appropriation — also a common practice in Japan, but one in which a lot can be lost in translation. Groups like Rats & Star take what they imagine to be African-American musical tradition and pump it through a J-pop machine, and it comes out unrecognizable. They may dress in the style of a 1950s American doo-wop band, but they don’t sound anything like one.

Cleveland thinks of Japan’s blackface singers and B-stylers in terms of "exotic othering." While the intent may be to show enthusiasm for something thought of as cool and different, the result can end up perpetuating racist stereotypes.

Cleveland stresses this is not in any way unique to Japan. But the key difference is that in America, for example, there are endless debates about it — there's awareness and constant self-policing. This country, of course, has its own enormous race issues to wrestle with. But those issues get talked about. In Japan, this doesn't happen.

Japan's racism puts the country's future at risk

From time to time in Japan, foreigners have led outcries over racial issues — such as McNeil with his anti-blackface petition, or a 1980s US-led campaign to ban the racist 1950s children’s book Little Black Sambo, highly popular in Japan (it’s since gone back on the shelves). But incidents like this never seem to spark a wider national conversation about race, and racist incidents get little domestic press coverage.

Even the flood of anti-Korean hate speech — an issue that's much closer to home, given Japan's sizable Korean minority and its history with Korea — has led the central government to respond not with legal measures, but with a suggestion that people be nicer to each other.

Why all the inertia? It goes back to this powerful myth of Japan as being an ethnically unified place.

As the country's population ages and its birth rate drops, it's badly in need of migrants

"In general this notion of racial homogeneity and conformity can lead to this lack of acceptance and understanding," said Cleveland. And it feeds an atmosphere in which understanding diversity is really not a priority.

It should be a priority. Japan's minorities face entrenched discrimination. As the country's population ages and its birth rate drops, it's badly in need of migrants to fill labor shortages and keep the welfare state funded. But Japan's problems with race make it culturally and in some ways legally hostile to immigration.

In February, a former adviser to Prime Minister Shinzo Abe sparked international outrage by suggesting apartheid could provide a good model for keeping immigrant workers separate from the Japanese. That is not a political climate that is ready to attract the migrants that Japan needs, much less assimilate them into society.

"Japan needs a more vibrant civil society that is more politically democratic, that allows for diversity and cultivates difference," said Cleveland. The education system would be a good place to start, he suggested: encouraging language-learning, and lessons about foreign cultures, would help.

"I don’t think for the most part Japanese education promotes an understanding of racial diversity, racial inequality, and various aspects of racial exploitation," he told me.

"Japan is a globalized society," he said, but sometimes, it's "very tone deaf."