Near as I can tell, odd sounding names aside, the current President of South Korea is not very popular. Also, he accuses his opposition party with colluding with (or being infiltrated by) North Korea.
So he declared Martial Law to impose his plans.
The South Korean people were pissed off and rioted.
The South Korean version of "Congress" did not support the martial law decree, and that seemed to be widespread criticism of the President's order.
So my guess, and this is fairly un-edu-ma-kated, is the South Korean leader is now a lame duck, stuck in an untenable situation, may perhaps be impeached (or whatever they call it there) and end up out of office in some way. Special election or some such thing.