The Ainu (Ezo?) would probably end up importing most of the Chinese package, though they might very well keep their native grains (foxtail millet, deccan grass etc) more than OTL Japanese did, thus leading to less reliance on paddy agriculture. So, one difference might be that the idea of a centralised government could be so difficult to enforce, and so expensive to try, that it would, at most, remain an ideal.
OTL Japanese were bad enough pirates to China, and they theoretically revered Chinese civilisation. Our Ainu might even conquering some of China's coasts, or at least be an even worse plague to east Asia. They might look further afield than China, too, and adopt more from India/Indonesia.
Buddhism and Confucianism have been so successful, they'd probably make inroads here, too. But Confucianism's reverence for tradition might end up reinforcing nativism, and Buddhism remain a slandered minority.
One detail...the Chinese have fox demons. If the natives have to fight them long and hard, they might feel the foxes are somehow the national symbol, or even claim some descent.