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.
Koichi Tohei was a fragile child and this is why his father gave him to Judo. With years Koichi was able to see the results of his hard training but soon, when he entered the Keio University for the Economics Department he got pleurisy.
Tohei did not wish to lose what he obtained with the Judo but was forced to replace his training with the Zen meditation and Misogi exercises. He joined the Ichikukai Dojo for that and recovered from pleurisy soon. This made him convinced that it was his efforts in training his mind and cultivating his Ki that had helped him to heal and recover.
Koichi Tohei came back in Judo but this time he was looking for something more than physical training and this is when his Judo teacher, Shohei Mori, recommended him to meet Morihei Ueshiba. Koichi did but had serious doubts about Aikido and Morihei Ueshiba had to solve them directly.
After only six months of training with O-Sensei, Tohei was sent to teach in a school and a military academy as a representative. Tohei Sensei was really good in taking the advantage of those who did not believe in a technical aspect of the Aikido and he made it a lot of times with the success. He also developed Kiatsu, a system of treating physical illness extending the Ki into the body through the fingertips. He is an author of numerous books on Aikido and Ki.
Sensei was the first one to expand Aikido outside of Japan. He went to Hawai, USA and Europe. He had to split with the Aikikai after the death of the O-Sensei and founded Ki Society and Shin Shin Toitsu Aikido which translates as “Aikido with mind and body unified”. Ki Society Aikido is now ruled by his son Shinichi Tohei. One of the notable Tohei’s students is Koichi Kashiwaya. Here’s an interview with the Koichi Tohei, his explanation on Ki energy and Ki principles.