Is there any way to use Korean letters in username on EUW server?

I was trying to create a new account on EUW server (too broke to change servers actually) and I wanted to put '기대^^' as my surname, however it says "The Summoner Name contains some characters that are not allowed: 기, 대. Please try again.", while I'm 100% sure I saw few people with usernames written in hangul on EUNE.. ;-;