There's at least one country where the tune never really caught on: Japan.
Online in Japan, stories have appeared, wondering why the country isn't into the song. This post, for example, is titled "For Some Reason PSY's 'Gangnam Style' Didn't Catch On Only in Japan."
For an anecdotal comparison, just compare the length of the Japanese Wiki page to the English language one. Or, more tellingly, ask grade schoolers in Japan about "Gangnam Style". When other Korean groups, such as Kara, hit it big in Japan, youngsters not only knew the songs, but also knew the dance moves, because those artists were all over television. PSY has been largely absent, save for news reports on how popular "Gangnam Style" is abroad. (Online in Japan, however, some seem to think think that the idea of a fat Asian guy wearing sunglasses and dancing about is probably humorous to Westerners—hence the song's popularity. Then, there are lighthearted conspiracy theories about people pressing F5 over and over again on YouTube.)
Japan hasn't been adverse to Korean pop music. It's been quite the contrary, actually. Back in 2010, Korean pop was all over the place, with both female and male Korean groups popping up on Japanese television and touring the country.
This was more than a passing fad, and the influx of Korean stars in the Japanese pop culture landscape seemed like it would be beneficial for relations. It wasn't that these Korean singers and actors were talented. They also were learning Japanese—with some of them showing quite impressive language skills—and showing an interest in the country.
Because of this, the Japanese public has come to expect Japanese language versions of K-pop hits. English speaking singers get a free pass, perhaps, because Japanese people all study English in school (or, more likely, because of the cultural dominance the language has). The Korean language, however, doesn't get that free pass, for a variety or reasons both cultural and historical.
PSY, however, was poised to make the leap. According to Japanese site Cyzo, it was announced earlier this year that PSY would make his Japan debut. PSY was to record a mini album with "Roppongi Style", a Japanese language version of "Gangnam Style", set against Tokyo's Roppongi and slated for a September 26 release. Then, out of the blue, PSY's people stated that this was mistaken information and that there would be more information announced at a later date. According to those connected to the music business, his Japanese language debut was put on indefinite hold.
So, what happened? This year, things between the two countries have been tense with Korea's president saying the Japanese Emperor should apologize for the colonial rule—something commenters in Japan said was to stir up Korean nationalism during the elections. Earlier this week, the President of Korea, Lee Myung-bak, denied ever saying that.
There's also a land dispute between Japan and Korea, which actually reared its head during the Olympics. The incident was viewed as unseemly and inappropriate in Japan, and the Olympics committee didn't seem to approve, either. The Korean soccer player who displayed a sign claiming Korean sovereignty over the islands was not awarded a medal.
All of this has cooled off much of Japan's interest in Korean pop culture. During the summer, thread after thread online in Japan was saying the "Korean boom" was over. People didn't seem to have the stomach for it after the political muck. Korean pop stars seemed largely absent from Japanese television.
There could be another reason, though, why the song hasn't captured the imagination of Japan.
A Japanese television rep explained the reason, reports Yahoo! Japan (via Rocket News): "PSY had already begun to be featured on Japanese morning variety news programs back in July, but the reaction from viewers was horrible. This was right around the time when Japanese media were under fire for over-promoting K-pop while attitudes toward Korea were souring, and the reason K-Pop became so popular in Japan in the first place is because Korean artists are known for being beautiful, so PSY looked completely out of place on screen. Even if he debuted in Japan, I don't think he would have sold very much."
The stereotype in Japan is that Korean stars are extremely attractive. The men are handsome and kind. There was even a stereotype, based on Korean soap operas, that Korean men were nicer than Japanese men. And the stereotype for Korean women was that they have very long legs and are extremely attractive.
"Gangnam Style" has attractive women in the video, but PSY is not handsome. For the Japanese, he probably looks more like some comedian, so people might wonder what the fuss is over the song. Japan has its own ironic music acts (Kishidan, anyone?), but PSY doesn't quite fit into the current Korean construct the country. PSY, however, probably could eventually hit it big in Japan, especially if tensions between Korea and Japan calm down. NicoNico News did a story about Japanese people talking about the song on Twitter, so there is probably interest. But, it will also take the Japanese mass media to ensure that the song explodes by having PSY pop up in commercials, variety shows, music shows—you name it. If he gets the same push that other Korean artists previously got in Japan, his music will go supernova. Rightly or wrongly, that's Japan style. But like that matters little when the song is already taking over the world.