Currently Japan is entering into the era of “shrinking society” after the long postwar economic development. It is still unclear how and to what extent such a turn will bring about changes in local society, but the concept of “shrinking” certainly stands at the center of current political debates, and begins to mobilize a variety of related actors by arousing a feeling of coming crisis. This article considers functions and mechanisms of “scale” narratives, such as shrinking, and, to do so, takes “overpopulation” problem in the 1950s as a symbolic and illustrative example. About a half century ago, this reverse view to the land once prevailed over the country in Japan. Losing vast territory in overseas colonies after the defeat of the World War II, Japan was obliged to manage more dense population on narrower land of archipelagos. Therefore Japanese Government emphasized overpopulation as an acute problem to be tackled, and tried to start development-oriented policies at a national level. And this must be accompanied with participation of ordinary citizens at a local level, so various cultural and educational settings for local mobilization were established, particularly by using the concept of overpopulation as a scale narrative. This article investigates these processes and consequences, focusing on two examples; one is Industrial Development Youth Corps, the other is an attempt of development education in Hokkaido University. At last, a historical transition from overpopulation to shrinking society in postwar Japan is summarized and discussed.