Eiji Mitani joined ORIX in December 1978 after working for TOSTEM CORPORATION for two years. After a number of positions in ORIX, he was appointed General Manager of the Branch Coordination Department in March 1999 and General Manager of Osaka Sales Department III in December of the same year. In January 2002, Mitani was appointed General Manager of Branch Coordination Department V and Deputy Head of the Tokyo Sales Headquarters in January 2002. In January 2003, Mitani was appointed as a Corporate Executive Officer and became an Executive Officer under a "Company with Committees" structure in June 2003. In May 2004, he was made the executive officer in charge of the Administration Center and the Sales Administration Department. In February 2005, Mitani was made the Head of the Tokyo Sales Headquarters. In January 2006, Mitani was appointed to the position of Group Senior Vice President and President of ORIX Auto Corporation.

Mitani was born in 1953.