TOKYO — The $9 billion that Japan’s Mitsubishi UFJ Financial Group injected into Morgan Stanley following the global financial crisis has paid off by contributing roughly twice the investment to MUFG’s profits over the past decade.

Friday marks 15 years since MUFG rode to the rescue and bought preferred shares in the U.S. investment bank after the collapse of Lehman Brothers, equivalent to about 900 billion yen based on exchange rates at the time.