Hirai Minoru was born on March 1903 in Okayama Prefecture. Strong background in iaido. Entered Kobukan dojo

In 1939 and became General Affairs Director in January 1942. Sent as representative to the DAI NIHON BUTOKUKAI in October 1942. Played major role in name change from AIKI BUDO to aikido.

In July 1945 received the rank of HANSHI from the DAI NIHON BUTOKUKAI. Established the KORINDO dojo in Shizuoka in October 1945.

In September 1953 he established the KORINDO dojo in Tokyo. In January 1954, combined Shizuoka, Okayama and Tokyo dojos and established the NIHON KORINKAI. .
 
         He died on October the 16 th, 1998, aged 94