Despite the remarkably serious problems caused by aging and population decline in Japan, there are very few books that inform the world about them in English. Through this book, a Japanese economic demographer clearly shows the various economic consequences of population problems in Japan, especially the impacts of continuing ultra-low fertility and the world’s highest life expectancy in the post-demographic transition phase. The explanation is at a basic level but covers the overall economic issues including labor, capital, technical progress, consumption, savings and investment from a demographic perspective. Finally, some remedies for economic growth in Japan are proposed. Because economic policies are expected to have short-term effects while demographic ones to increase the fertility rate need some time to take effect, earlier books about the Japanese economy have hardly ever dealt with demographic policies. Furthermore, this book directly addresses the integrated economic and demographic policies appropriate to Japan. These are different from the French natalistic social policy, the Scandinavian policy of a work–life balance or the immigration policy in Australia or the United States. This book emphasizes the power of local communities in Japan as a part of East Asia. In this sense, the book provides a new key to readers who are interested in the future Japanese economy and population.