I need your help guys

North Korea is region locked in real life.

umm , does north Korea even have access to steam?

Korea doesn't have region and ACRTAG restriction lock, they're ROW.

Well i guess you're right about North Korea :D but the one that I'm not sure about is South Korea. I think they are part of ASIA region but I'm not sure between that and SEA.

I was asking you that because I sent a humble bundle leftover key (from previous game bundles) as gift to a friend who is in South Korea, and he said that he cannot activate it there which is weird. I was not sure if North and South are linked to each other. but from the way North Korea looks I understand they are not :)

They're mostly row. However, like Germany and Japan, there are a handful of games that can't be activated in South Korea.
I'm pretty sure you're talking about the current humble bundle. Total War cannot be sold/activated in South Korea