In this paper, we discuss the current status and function of main bank relationships in Japan, based on the results of a survey conducted on transactions between businesses and their main banks and interviews with companies and banks. First, we surveyed transactions between 500 large Japanese companies and their main banks over a period of 35 years, from 1973 to 2008, and examined recent changes in these relationships. As a result, the following facts were discovered: (1) the relationships between companies and their main banks are static, and most companies have not changed their main banks; (2) during the 1980s and 1990s, the significance of bank borrowings and main bank borrowings declined, reflecting the lower debt ratio of companies; (3) however, after the 1990s, the dependence on main bank borrowings remained almost unchanged; (4) the relationship between companies and their main banks in terms of shareholding and the dispatch of officers weakened in the 2000s; (5) when companies engage in new ways of financing (e.g., commitment lines, syndicated loans, etc.), they often ask their main banks to become the lead manager; and (6) the main banks and their securities subsidiaries have a large share of the issuance business (acting as the financial agent and the lead underwriter, etc.) when companies issue corporate bonds. These survey results show that companies still have a close relationship with their main banks, but a weakening connection in terms of loans, shareholding, and officers. So why do companies still maintain a strong relationship with their main banks? By conducting interviews with both companies and banks, it was revealed that there was still a tacit understanding between the parties that the banks would provide the companies with funds when necessary. The banks would also offer support should the companies face financial trouble, in exchange for the companies' loyalty. This implies that the role of the main banks is to hedge financial risk. Despite the progress today in the formation and globalization of financial markets, there is still considerable risk of companies going bankrupt. It was also discovered that the companies asked their main banks for the provision of information and financial services. Putting these findings together, it is conceivable that the provision of risk-hedging and financial services has become an important function of main banks in Japan, which used to focus on monitoring and governance.