From a half-Japanese consultant based in Kyrgyzstan:
「キルギス人と日本人は元々同じ民族であったが、魚が好きな人は東に行って日本人になり、肉の好きな人は西に言ってキルギス人になった。」と言う話をよく聞きます。
I often hear, “The Kyrgyz and Japanese were once the same people, but those who liked fish went east and those who liked meat went west.”
I am throwing this in the same bucket as the 日ユ同祖論. Looking at Kyrgyzstan on a map, it doesn’t look like that kind of country that would have a huge population of fish lovers to begin with, so where did the twain originally reside, pray tell?
Lake Baikal.
Peter, I would say that technically it’s closer to the Altaic Hypothesis.