What if the shogunate never devellops, or at least never holds, as a political institution in medieval Japan, while the emperor doesn't recover the power he lost IOTL, at least for a significant period of time?
What would have allowed that, and which kind of outcome would have been likely? A modus vivendi between clans, a slow recover from the emperors, balkanization of Japan and no Empire in the long run, easier foreign conquest?