^^
So, no-one thinks that any of the later Ainu rebellions could have plausibly been successful (Koshamain's Revolt in 1456, and Shakushain's Revolt from 1669-1672?)
And there's another interesting possibility, later on; IOTL, a private merchant from Yakutsk by the name of Pavel Lebedev-Lastoschkin was enlisted as a volunteer for a mission to help the Tsardom of Russia open Japan at far less cost to the government than if they had sent official emissaries or military forces; seeking the profits from either Japanese trade goods or furs from Hokkaidō. His first attempt failed entirely when his ship sank in the Sea of Okhotsk. But he, along with another merchant named Grigory Shelikhov, was granted trade monopoly over the Kuril Islands. The plan was to sail to Uruppu, one of the islands, with an expedition crew and about 40 settlers. They would set up a small colony town near Uruppu, try to integrate the local Ainu population and enlist their services to guide them down to Japan. This second expedition failed as well when, after reaching Uruppu in the summer of 1775, the ship sank in a storm.
Lastochkin tried yet again, this time bringing a number of extra ships. It was now 1778, and the expedition met with the Lords of Matsumae clan, the Japanese guardians of the northern borders, for the first time. They bestowed gifts upon the samurai lords, and asked to trade. The samurai informed Lastochkin's party that they did not have the authority to make such agreements on behalf of the Shogun, but that they should return the following year. Upon doing so in September 1779, Lastochkin's gifts were returned, he was forbidden to return to Hokkaido, and informed that if he wished to trade, he should inquire at Nagasaki, on the southern island of Kyūshū, and inconveniently far from Russian holdings.
Latoschkin returned to Uruppu to plan his next move (where a trading outpost had still been established, in spite of the lack of settlers)- but at this point, an earthquake caused a massive tsunami in June 1780, which stranded the main Russian trade vessel some distance inland and destroying the Russian trade outpost. This finally convinced Latoschkin to give up on seeking trade with Japan, and he finally accepted failure in his efforts to open Japan to Russian trade. But this offers a few potential POD's- for instance, WI the Matsumae Clan had decided to make the agreements to trade with the Russians, effectively breaking away from the Shogunate?
Or, WI Lastochkin had decided to establish his private company's suzerainty over the Ainu tribal kingdoms anyway- encompassing the Kuril Islands, Sakhalin and the vast majority of Hokkaido (with only the Matsumae Peninsula under the control of the Matsumae clan, and with the vast majority of Hokkaido effectively serving as an Ainu reservation until after the Meiji Restoration)? Or WI the Russian colonial vessel hadn't been sunk in the storm, and a colony town had been established on Uruppu as originally planned (with more colonial settlers arriving to boost their numbers, and other colony villages being established on a couple of other islands)?
Couldn't it be plausible in such a scenario, where the Russians take control of the Ainu and their homeland of Moshir during the Great Game (before the Meiji Restoration gives Japan the chance to do so), for TTL's Ainu Moshir to be established as a single self-governing nation, and to gain/regain its unified independence by the present day, in a similar manner to Uzbekistan and Turkmenistan?