Ainu history includes a dramatic socio-cultural transition, reflected in landscape formation, between the Epi-Jomon (third century BC-seventh century AD) and the Satsumon period (seventh-thirteenth centuries AD). This article examines the nature of this landscape shift, revealing, between the Epi-Jomon and the Satsumon, a variety of profound changes in the ways in which land and bio-resources were used for subsistence activities, even though natural and physical environmental cycles underwent no fundamental transformation during this time. These results lead us to conclude that the Ainu landscape-as the product of a system of ecological and socio-cultural adaptation, described in the historical and ethnographic eras-was established in the Satsumon period. This landscape shift is illustrated by a case study of a hunter-gatherer society directly influenced by the market economy and political systems of outside societies and nations during East Asia's medieval stage, before completing its spontaneous process of 'Neolithizaiton'.