Japan and Korea are apparently in a dispute (again) over a tiny island somewhere in the Sea of Japan/East Sea. According to the Wikipedia entry, Japan had claims to the islands and effectively occupied it until the end of WW2. After the war, the allies didn't quite make the status of the islands clear, and it was left out of the 1952 Treaty of San Francisco (which settled most other disputed islands) as well. In January 1953, the South Korean government ordered the army to enforce their claim over the island. The Japanese coast guard responded, an armed skirmish followed, a Japanese ship was sunk, Japan offered to take it to International Court, the Koreans rejected, and South Koreans have occupied it since. In fact, the official South Korean position says they have "effective domination" over the island, which as far as I can tell, is another way of saying "we took it over by force, deal with it."
Being (technically) Japanese, I'm constantly afraid of sounding fascist, but in this case, I gotta give it to the Japanese. You can't criticize another country for invading and colonizing your own country, then try and do the same (that is, critcizing is justified, doing the same is not). Having said that, the South Korean government apparently "considers sovereignty over the islands as more important than good relations with Japan" (from BBC article). In that case, I say give it to the South Koreans. Having good relations with your neighbors, especially neighbors you've been bad to in the past, is much more important than a tiny island (although I guess it's more about the rich fishing grounds around the island, than the island itself --and the island may also have some strategic significance, since it was used as a naval base during the war).