the japanese govt about 1&1/2 centuries asked them to farm. If they lived in huts, likely because their habitats were sparsely populated and they wouldn't exhaust the wild life stock easily. Regardless, their interaction with main stream chinese was brief.

"Humans first landed on Hokkaido at least 20,000 years ago, probably arriving from Siberia via a land bridge in search of a less frigid environment. By the end of the last ice age, their descendants had developed a culture of hunting, foraging, and fishing. Large-scale rice farming was a southern phenomenon; the north was too cold, too snowy..."

https://www.smithsonianmag.com/science-nature/how-bear-worshipping-group-in-japan-fought-for-cultural-relevance-180965281/