If you're female and single then I suspect it may be tricky. If you're married then it may be easier if your husband is going too. Countries play stupid games with Filipinas, as I found out when I married one. We applied for visas to go to Egypt (in principle I could have got one on arrival, but it was cheaper to apply for one in advance and no more effort since my wife needed one anyway), and what my wife got next to her visa in her passport was handwritten "Must enter Egypt with Mr PDLM".
This, of course, was totally illogical - if what they were trying to prevent was us going there, me pimping/selling her off and then leaving, then what they should have done was write in MY passport "Must leave Egypt with Mrs PDLM". But I guess they know that Filipinas are so used to this abuse that they will just accept whereas a Brit would scream and create a diplomatic incident about something like that being done to his passport.
Sorry, that was a bit of a sidetrack - I don't have any specific experience of the Korean situation, sorry.