Minamata city is well known as the company town of Chisso Corporation, as the site of Minamata disease and, in recent times, as a city with environmentally friendly policies. The postwar experiences of Minamata city are often compared to a microcosm of Japanese modernization. A few decades earlier, the city faced and tackled several problems that most non-metropolitan cities currently face, such as an aging population and economic decline. There are meaningful lessons and suggestions we can adopt from Minamata city for sustainable development policies suited to non-metropolitan cities. This paper focuses on the economic history of Minamata (which includes not only Chisso but also other manufacturing companies and industries) and the dynamic relations between its local economy and politics. In Minamata, social tensions, such as those between the perpetrators and the victims of Minamata disease and between Chisso's labor and management, gradually disappeared due to reconciliation efforts and generational change. Minamata city office changed its vision of future development from being an industrial city to an environmentally friendly one, bearing in mind not only the experiences of Minamata disease victims but also the city's varied environmental resources. The residents of Minamata offered their support for these policies in recent mayor elections. Nevertheless, new problems began to emerge in the city. Jobs for the young had been limited for a long time, especially for men and those who were highly educated. One of the reasons for this is that Chisso prioritized retaining employees and restricted new hiring. Besides, the economic dominance of Chisso prevented local leaders and enterprises from growing. As a result, although Minamata's town planning, with its emphasis on environmentally friendly policies, received much attention and support, those policies could not be effectively implemented due to a lack of local human and institutional resources. Recently, however, young residents have begun to construct new social networks. It is worth noting that they share environmentally friendly visions. We can regard these kinds of movement as the results of continued efforts by Minamata city office and citizens. The economic and social dynamics of Minamata and the problems mentioned here are likely to be common to many non-metropolitan cities. Those cities must not be nearsighted about depopulation problems, but should investigate and try to maintain the conditions needed for long-term social and economic sustainability.