Career
Mitani is from Fukuyama, Hiroshima and began judo at the age of a first grader. He belonged to Japan Highway Public Corporation after graduation from Kinki University in 1991. Mitani was good at Ippon seoi nage, Osotogari and Uchi mata sukashi.
He was also participate All-Japan Championships 9 times from 1990 to 2000.
After retirement, Mitani coached judo at Japan Highway Public Corporation and All-Japan Youth Team. 1990 - All-Japan Championships (Openweight only) 3rd.