The Korean Studios, handle a lot of out-sourcing from Japan too.
The concept design and game bible are developed in house and then production is farmed out to korean studios.
There was a similar model with tv animation in the 80’s and 90’s, you will see a lot of Korean and Japanese surnames on kids tv shows. But their indigenous games market is very strong too. They have a large young population absolutely addicted to online games. The internet cafe games culture is popular.
You know they are into their games when you see stories like this coming up every now and then.
Gamer dies after marathon game session.
http://news.bbc.co.uk/2/hi/technology/4137782.stm