My favorite Korean illustrator (the only one I know, really) is Kim Hyung-tae. He's done a lot of concept art and character design for computer games in South Korea. The deluxe version of Magna Carta comes with the most impressive game manual I've ever seen. Hardbound and filled with art from cover to cover, even if you can't read Korean it's worth buying the game just to have this book.
KHT Fansite
Character pages from Magna Carta (in English)