The 38 Years' War was, from what I understand, the final major conflict between the Emishi and Yamato people. It began with a strong showing by the Emishi, who struck numerous blows against the Yamato kingdom, and it seems as though it was only the betrayal of the Shiwa tribe that did in the Emishi. So, what if the war had gone the other way? What if the Shiwa had not changed sides? Could such a victory result in the Emishi tribes banding together into a more permanent kingdom and survive? How would the history of Asia change if Japan was only half the archipelago?