I'm sure this has already been asked but I have a hard time finding a thread on this so i might as well ask : what would happen if the Shogunate won the Boshin War and captured the Imperial leaders (among them of course Meiji) ?
Japan would have surely continued its modernization since it was the Tokugawa who had begun it.
But I have a hard time imagining the politics of the country after it. The Tokugawa can't abolish the Empire but I guess the Emperor would continue as a figurehead, always watched by men of the bakufu. But if they liberalize, then I don't see the system continue. A dyarchy with the Shogun and the Emperor would continue to provoke tensions and surely provoke instability in governments.
On external diplomacy, would Japan still pursue expansionnism in the Pacific ?