Wikipedia's back, and I spent a good amount of time there (and on a few other sites) reading about the other Korean communities in Asia apart from North Korea and South Korea. There are also:
- Sakhalin Koreans - A very small number of ethnic Koreans living on Sakhalin Island, having been captured by Japan during the war and shipped there for forced labour and then stranded by terrible international politics
- Koryo-Saram - Ethnic Koreans who spread out into China and the Russian Far East ages ago, some of whom were later shoved around inside Russia during the war for fears of being infested by Japanese spies. Many of this (much larger) community don't still speak any dialect of Korean.
Eastern Russia is a real grab-bag of ethnicities though; one of the more interesting things I learned ages ago when I started to take an interest in the region is that the Turkic people stretch all the way from Turkey through Azerbaijan and Turkmenistan all the way to the Pacific. It might've been when I heard a friend say they were heading to Azerbaijan for PeaceCorps and state that they started to learn Turkish before switching to specifically Azeri language materials because the former were more readily available and the languages are very close; that seemed like an interesting fact to dig at.