How far back would one have to go, and what would be a good point of departure from the historical timeline, in order for Japan not to be a unified country, but instead several independent ones?
THe SEngoku period is another great time for a POD. If you butterfly away Oda Nobunaga then Japan could remain divided well into the 1800's. By then the western powers will be there and picking sides. You'd be looking at a big proxy war.
That could be "remedied" by having the empire split by local warlords using rival pretenders for the imperial throne as puppets. Don't know whether that really would be worth the bother, though, with the Emperor being such a politically weak figure during that period.A very good point, although there is a likelyhood that Japan will remain "united" under the empire despite the lack of a reigning Shogun or Regent, which may or may not be an issue for the OP.
Even if you butterfly Oda away there are still a number of Warlords who had the talent and resources to unify Japan during the Sengoku period. Takeda springs to mind, as does Uesugi.
The idea of being Japanese was not something to be quelched easily, Japan holds the oldest surviving Dynasty in existence and were revered as virtual Gods. You could not oppose the Emperor until well after the Europeans arrived if you wished to survive very long.How far back would one have to go, and what would be a good point of departure from the historical timeline, in order for Japan not to be a unified country, but instead several independent ones?
I was also wondering what a good PoD would be to have three Japanese states: a Satsuma Republic, a Choshu Republic and an Ezo Republic. Could it be just after the Meiji Restoration?
That one might be a republic, ok. All three? The japanese were pretty monarchist.