There are some koreans that do full nudity with sex, but they will never show their face. It's not as common now days but like 10 years ago there was way more. Also, a lot of sex videos from korea are from spy cams or revenge porn.
Also as stated by
oraneknight , it's illegal for a korean citizen to make porn, even going abroad is illegal. Some girls has gone to Japan to make a couple of videos but some has been punished for it.
Some that has done OF that I know off is
Chocoletmilkk
xoxo_yuri
bibicouple
kkkkhhhhkh2003 (Can't find anything on her anymore)
Henry_sera (doesn't have a thread here but she does cuckold and it's decently easy to find if you search for it)
What all of these have in common is that none of them show their face. The only one I know that has shown her face is
Red_Dxxx.
There are some more that have nude videos/photos but most of them are from sending to people and not uploading themself.