This text is an attempt to explain Japanese regional structure and associated dynamism in terms of urban systems. It is extremely effective to use the urban systems approach to explain the regional changes in today's Japan, which is undergoing changes wrought by economic globalization and the information revolution. This is because the transformation into a service economy has become the key component of the economic activities of cities, linkages are being mutually strengthened, and regional development is being determined by the interdependency of cities. Readers hoping to gain an understanding of the regional geography of Japan may feel that the structure and content of this book are lacking something. However, it is not the intention of this book to systematically paint a total geographical image of Japan within the context of East Asia. Instead, by focusing on urban systems theory, it might be possible to theorize about the factors related to the changing geography of Japan, such as the growth and decline processes of Japanese urban systems, the strengthening of ties among cities and associated factors, and the expansion of socioeconomic exchanges with cities overseas, from a perspective that is different from the conventional approach.