This study examines the inequalities in population structure across small communities in mountainous areas and identified the features of small communities with stable populations in the Kyushu mountainous area. First, the study focused on identifying differences in population in eight mountainous regions with a significant share of agriculture and forestry activities, by analyzing the population pyramid form using census data. Second, the ethnographic method was used to study and document the features of the population-stable areas in the Kyushu Mountains. This involved intensive fieldworks, including participant observation and interviews. The study analyzes the data from observation and interview surveys to understand the perceptions, meanings, and behaviors of individuals living in remote rural communities. It utilized the modified grounded theory approach（M-GTA）, a qualitative research method, to analyze the process of returning to live in the rural community. The study, then, illustrated the “theory of sustainable rural community”, which elucidates how stable populations can be sustained in rural communities facing remote and uneasy situations. The mechanism is found to be based on a cyclically interactive relationship among concepts related to “protecting and accumulating communityʼs capital”, a system of “circulating time with psychological and physical aspects”, and the foundation of “agencies embedded in the community”.
