In mountainous areas in Japan, depopulation and aging issues are being serious. But there is not enough power and willpower to reactivate by themselves. Therefore, new collaborative activities towards reactivating these areas with supporters from outside such as Community-Reactivating Cooperators have been started as national policy. On the other hand, cooperative activities with outsiders have some issues such as depend on cooperators and losing independence of inhabitants and deteriorating relationship between the two attribute. Therefore, process design of acceptance and cooperation is important in these supporting activities. This study aims to clarify the change of social role of outsiders, and process of acceptance and cooperation in hilly and mountainous areas. Firstly, we understood the outline of theory of Community-Reactivating Cooperators on local government and supporter's activities. Secondly, we clarified the process of gaining acceptance by inhabitants, through communication with cooperators. Thirdly, we clarified the role transfer process of supporters. And finally, We clarified the acceptance process and role transfer of supporters in depopulating and aging local region. This study is identified as understanding detailed process of acceptance and cooperation, and change of social role of outsiders in the new cooperative activities in hilly and mountainous areas in Japan.
