I have been in shipping for over 10 years and last year started my own Freight Forwarding company. I will look into this for you tomorrow when I get back to the office as shipping bonsai can be a problem. Bonsai from Japan require a phytosanitary certificate but I'm not sure about Korea, let's hope it's not required because if so your tree will have to be fumigated first and I don't know what effects this will have on your tree.