This book describes and clarifies how certain problems can be resolved in Japan and Asia. For the future, the focus should be on Japan, which can provide "common knowledge" as a public good. The book collects the results of researchers in Japan, China, South Korea, and Indonesia on declining birthrates and aging, rapid technological innovation and societal changes, and recovery from natural disasters.Chapter 1 covers Japanese social welfare system reform and transformation of social governance. Chapter 2 deals with the decreasing birthrate and national security. Chapters 3 to 5 discuss three aspects of the impact of modern technology on Japanese society. Chapter 6 and 7 include the research results on recovery from the earthquake disasters in Indonesia and East Japan. Through reading this book, the increasingly necessity to capture Japanese studies in Asia as a public good can be understood. The authors believe that sharing of knowledge as a public good is of great help in solving problems for the future.