Reisuke Ishida was one of the more wellknown individuals from the former Mitsubishi & Co.* He loved to be on the front line of business, and of his 34 years working at the former Mitsubishi & Co., 27 were spent at overseas offices. After graduating from the predecessor of Hitotsubashi University, he began his career at the former Mitsubishi & Co. in 1907. He then went on to work at the former Mitsubishi & Co.'s offices in Dalian, Seattle, and Bombay (now Mumbai), before assuming the role of General Manager of the New York Office.

Here he proposed the company begin trading tin. Although the business started small, trade volume was gradually expanded. Eventually Mitsubishi was chosen as the sole agent of the world's largest tin manufacturer in the UK. Utilizing its position as sole agent, the former Mitsubishi & Co. continued to expand the business. At its peak, it handled around one quarter of all tin imports into the U.S., and famous American companies including U.S. Steel, General Motors, Ford and American Can Company, all became key clients of the former Mitsubishi & Co.

Reisuke Ishida became a managing director in 1936, and then progressed to representative director in 1939. In the autumn of 1941 when relations between Japan and the U.S. had reached breaking point, he joined together with leading figures in the financial world to try to convince the Japanese government to avoid conflict with the U.S. However his efforts proved unsuccessful. He left the former Mitsubishi & Co. soon after the war began.