I remember Blam posted an article about Samurais being Ainus. I've seen how Samurais are depicted and they remind me of Ainus. In the movie, Last Samurai, those Samurais were more Ainu than Japanese.
Depends to some degree on how you "count" the Ainu in the South in the 1300s.
The Samurai, however, are predominantly of the same ethnotype as the Emishi and Ainu (for whom there is both a geographic and cultural difference of serious note).