those are extremely biased unemployment rate. It's been known that unemployment rate conducted by government is totally a bullshit with too many restrictions to be categorized as "unemployed".

There are many articles (written in Korean) that list those restrictions, for example: http://slownews.kr/19261

For young people, more realistic unemployment rate is 34.2% or 1.8million according to this article: http://www.yonhapnews.co.kr/bulletin/2016/06/13/0200000000AK...

I believe joonhocho was speaking more about youth unemployment than overall unemployment. From the same web site, that rate appears to bounce around in the double digits:

http://www.tradingeconomics.com/south-korea/youth-unemployme...