The Liancourt Rocks are a group of islands off of the coast of Japan and Korea that are currently administered by Korea. The ownership is disputed however, and both countries go through ridiculous efforts to claim that the islands are theirs. It has a huge deposit of natural gas in the waters surrounding it, but it is mostly deposited for nationalistic reasons and pride.
The Japanese have tried to settle the dispute by taking the case to the International Court of Justice (ICJ) 3 times, but the Koreans have refused it all 3 times, claiming that they have no reason to do so. North Koreans, although technically still at war with South Korea, support the South's claim.
The Liancourt Rocks are called Takeshima and Dokdo, respectively, by Japan and Korea.
Japan: Please get off our land.
Korea: STFU it's mine! Come with a military if you want it!
Rest of the world: What the flying fuck are the Lioncoot Roks?