I speak Korean.
You can't register at that site. There's a really assanine reason too... The Korean government is extremely xenophobic in how they handle the "Korean" vs. "foreigner" distinction...
The first two inputs are for:
1) ID
2) Password
No problem so far... The next 2 inputs are where you get screwed:
3) Name
4) Citizen registration number (Social security number)
It is almost impossible to use a Korean website unless you are a Korean citizen. You don't have #4, and therefore cannot register.
When the Korean government pulls its head out of its butt and finally passes some legislation that will allow ecommerce inside of Korea for non-Koreans, Hell will freeze over.
When it comes to overblown redtape and general idiocy in government and bureaucracy, Korea puts the rest of the world to shame.
In short, don't try to do business in Korea, because even when you try to give them your money, they will make it impossible. (I can provide many examples for the skeptics out there.)