This book is a rarity in that it conducts a comparative study of life satisfaction between Japan and China over a wider area and time period, filling a gap in empirical research on life satisfaction. Unlike many other countries that have focused primarily on the pursuit of economic prosperity, this study objectively examines the relationship between economic growth and life satisfaction. This study examines various aspects of the proportion of individuals who report being satisfied with their lives, including time series and single-year comparisons, as well as the level and rate of economic growth. This study conducted independent questionnaire surveys in China and Japan, analyzed the impact of absolute income and relative income on life satisfaction, and then objectively examined and compared life satisfaction in China and Japan. Furthermore, this study proposes that real disposable income exceeding $8,000 is an important signal of a shift in the pursuit of "spiritual wealth" from an emphasis on "material wealth" among the Chinese and Japanese. In particular, questionnaire surveys, one for all of Japan and one specifically for Kyoto City, were conducted on the impact of the global pandemic COVID-19 on life satisfaction, and it was found that the original "US$8,000" line has risen to "US$15,000". This study not only enriches the understanding of the relationship between economic growth, COVID-19 and life satisfaction, but also provides a new perspective for policy making.