Koichi Tohei (20 January 1920 – 19 May 2011) was a first one to be promoted to a 10 Dan by the Morihei Ueshiba ever. He taught people like Hiroshi Tada, Seigo Yamaguchi, Mitsugi Saotome, Sadateru Arikawa, Kazuo Chiba, Yoshimitsu Yamada, Steven Seagal and many others.
Yasuno Masatoshi was born on September 7, 1948, in Kanazawa city which is in the Ishikawa prefecture, Japan. Yasuno Masatoshi is a Hombu Shihan with an 8 Dan Aikikai rang and is considered to be Yamaguchi Sensei’s technique heir along with the Seishiro Endo, Yoshinobu Takeda and Christian Tissier.
Hiroshi Tada was born on December 13th, 1929 and is the only living 9th Dan Aikido Aikikai holder. He entered Hombu Dojo in 1950 and doing aikido now for 67 years! He was just always there, he knows them all, and seen it all happened and changed with his own eyes.
Koichi Kashiwaya is a Koichi Tohei’s disciple, 8th Dan in Shinshin Toitsu Aikido and an Okuden in Ki Training. He was appointed as a Chief Instructor for the Ki Society USA by Tohei Sensei himself.