Hey there-
I am stationed in Yongsan (Army) for 4 years now. I think you are SOL,
would be hard finding one here in Korea. I saw advertised that Osan had a PPL program..........but no instructors to teach the class? You should call the aviation unit up at Casey and ask about CFI's. I know they have some. It'll just take some searching.

I move back to the states in August this year. I will just wait til I get there to start my PPL, where I know there are plenty of places all over to complete my PPL, no matter where they send me. I will either be going to Fort Hood, TX or Fort Polk, LA.
I can't wait to get my training started!