Have you looked at prison terms? people in Korea don't smoke cannabis, their possession charges are unreal, I always wanted to go to Korea but after I read about their drug policies I can't give them my tourist dollar.First thing I do when I look up a country is look into their drug policies if they can lock up their own citizens for 10 years for smoking a joint they can lock up my foreign ass for just as long.
Countries that the USA helped destroy and rebuild tend to have absolutely nuts drug laws.
I got a buddy who teaches English over there, he says they'll get drunk every night of the week and eat horrible food but "illegal" drugs are crazy forbidden.
edit : obviously someone in Korea will smoke pot, however it's not like China where the stuff is growing everywhere. I doubt Koreans will be open enough to sell you seeds with such a great risk.