The rapid decrease in and the aging of Japan's population seriously influence the sustainability of municipalities and communities. The Japanese government is preparing several policies for preventing population mobility, directed especially toward slowing the movement of the younger generation from local areas to central metropolitan areas. Even though these policies are accepted in many municipalities, the amount of abandoned farm land, forests, and houses are increasing in rural areas. In urban areas, public buildings, schools, factories, and shopping centers are getting older and are used less. In fact, it is difficult to manage the infrastructure as well as the decreasing population in these areas. Though such movement is ongoing, people's activities related to using and maintaining common resources are decreasing; thus, social relationships centered on common resources in local and urban communities are weak and thin. Therefore, we must develop ideas and methods for rebuilding these social relationships. For this symposium, we invited three specialists. The first speaker was Dr. Ko Fujiyama, who analyzed the limited circulation of the local economy in rural communities. The second speaker was Dr. Masahide Hayashi, who examined several rules for picking mushrooms in the local commons of the forest area in Tadami, Fukushima Prefecture. The third speaker was Dr. Takeshi Hamada, who reviewed the traditional rules for catching abalone—primarily along the Sanriku coast—and the historical background. The speakers discussed the actual conditions in each area and offered some suggestions for sustaining social relationships and rural communities. After the presentations, Dr. Takeo Nishimura and Dr. Satomi Tanaka took part in the discussion. We acquired good information and suggestions from each presentation and the subsequent comments. We understand that differences in logic and rules apply when using common resources according to social, economic, geographical, and historical conditions. Thus, we need to discuss and devise optimal situations in local areas for rebuilding sustainable communities.