The map below visualises the article length of every English-language Wikipedia article in Japan, Taiwan, the Korean Peninsula, and eastern China.
It is Japan that really stands out on this map. The country glows with content in contrast to its neighbours which have much sparser layers of information defining them. The yellow dots in linear patterns that crisscross the country suggest that some diligent editors have been creating a lots of short articles about the entirety of the Japanese railway system (e.g. the list of every station in the country).
Even ignoring the prominence of information about the Japanese rail system on the map, you can see that the Tokyo-Yokohama metropolitan region is represented by a thick cloud of information that is much broader than the equivalent layers of articles about Seoul, Shanghai, Hong Kong, and Taipei. Some of this can be explained because Tokyo is a larger city, but it also remains that there is simply more information created about Japan than any other country in the region.
As always, more maps soon...