Mike Sigman wrote:
IIRC, the current Korean language is not related to the Japanese language. This has been a puzzle for some time since it turns out that genetically the Japanese are obviously from Korea (except for the Ainu, of course). The current explanation of the different languages is that ancient Korean records show that there were six small kingdoms in Korea, each with their own different language. During the typical conflicts, one of the kingdom's people were driven to Japan, more or less.
What is the source of your info here? For example, there is a book by Chris Beckwith: Koguryo: The language of Japan's continental relatives
. I have not seen it have heard Koreanists disagree with what it says - that he draws big conclusions from minimal info. The fact is that no one really knows about particular languages as there are few records and therefore little to study. Also, modern Korean grammar is really quite similar to Japanese such that anyone studying both will immediately have no doubt they are connected in some way.