The director of Chuu2 actually apologized for this sequence. It's probably not obvious to a western audience, but it's an insulting gesture aimed at Koreans. It's something that you see mostly in the context of a 'wacky news from Korea' segement on a news/entertainment or variety show. They will show Korean news coverage of victims of fan death, and the Japanese commentators do this little twirling motion to make fun of the idea, since people in Japan consider fan death itself a myth.
It used to be widely believed in Korea that fans would burn all the oxygen out of closed rooms, causing people to suffocate in their sleep.
[spoiler] most deaths attributed to "fan death" in korea are actually caused by exhaustion and dehydration from playing too much fucking starcraft
>since people in Japan consider fan death itself a myth.
That's probably because it's a myth.
Koreans are so superstitious they make Japanese people look like English empiricists. And it's extremely common for Japanese people to believe in and have a terrible fear of ghosts.
Asians are superstitious about a lot of weird shit. Koreans are no exception. Many of them believe running a fan in a room at night while sleeping will kill you. They come up with different theories as to why, each dumber than the last. Because Asians and bullshit superstition. It's similar to Asians' collective adherence to tradition, when compared with those of European descent.