For instance, horse riding and rice agriculture, neither of which were present in ancient Hokkaido, were both central to Emishi lifestyle.

[7] A study of pottery residue on Rebun Island sheds light on how the Satsumon culture adapted to a new environment.

Unlike their mainland counterparts who combined farming with hunting and gathering, the Satsumon people on Rebun Island appear to have relied more heavily on exploiting marine resources like fish and shellfish.

This shift in subsistence strategy suggests that the island's ecosystem was not ideal for their established practices of mixed farming and hunting.

Some see them as immigrants from Tōhoku, others as indigenous chiefs who had a special relationship with the government of the mainland, and that such a scale of tomb could be made by normal heads of family.