This chapter carefully computes the value added (income) generated by the Japan’s financial and insurance industry, particularly the banking industry, over a long period starting from the interwar period, while the primary focus of the analysis is the post-WWII period. Specifically, this chapter outlines the evolution of the Japanese banking industry’s business model and its prospects with reference to the developments in the United States. Although similar studies exist overseas, to our knowledge, Ono’s work is the first to examine the evolution of the banking industry in Japan over such a long period. The study shows that the share of the banking industry in Japan’s economic activity increased from the mid-1950s to the late 1980s but has been declining since the 1990s. During this transition, net interest income from deposit and loan operations, the largest source of income for banks, has declined significantly, while fees and net trading profits have increased. In contrast, in the United States, income related to securitization businesses declined after the global financial crisis, but income from traditional banking operations remained stable. In addition, Mitsuru Sawada’s commentary for Ono’s study, “Recent Trends in Banking Business Models Through Insights from Consolidated Financial Statements,” highlights the conglomeration (diversification of business) in the banking industry through financial subsidiaries as a result of the deregulation of business activities since the 1990s. He argues that by focusing on consolidated financial statements, the shift from deposit and loan operations to other forms of banking operations has progressed even more rapidly than Ono’s study indicates.