The link between Koguryo and Japanese

A couple of weeks ago, marxy blogged about Christopher L. Beckwith's book "Koguryo: The Language of Japan's Continental Relatives," which focuses on a possible link between the Koguryo language and Old-Japanese. Marxy's entry is a good summary of the book's argument, and he also links to a PDF file showing some similarities between (Old-)Koguryo and Japanese.

And it gets more interesting: when browsing through Google Books today, I found out that Beckwith's book is available in "Full View" format, so you can read the complete work online! I've skimmed through a couple of chapters, and it's very intriguing to see e.g. the similarity between kuchi (meaning "mouth" in Japanese) and its equivalent in Old-Koguryo: kuərtsi. Or tani ("valley" in Japanese) and tan in Old-Koguryo. And there's much more.