Zenzaburo often accompanies Morihei on his travels and seminars. He also trained at the Omoto kyo center in Takeda.
In December 1935, the Japanese government decided to end Omoto kyo, and as a result, training had to end in Iwama. Mitsunosuke Akazawa was even arrested for several weeks.
In 1937, at the behest of Morihei, he began studying Kashima Shinto ryu with his son Kisshomaru. In the Kashima Shinto ryu records, there is a keppan (blood oath that is made when entering the ryu) in the names of Morihei Ueshiba and Zenzaburo Akazawa dated May 16, 1937.
At the request of Morihei Ueshiba, Kobukan (also Kodokan at the request of Master Jigoro Kano) was visited by masters of Kashima Shinto ryu, especially Masashige Aoki, where they taught this martial art.
Morihei allegedly did not train himself under their leadership, but he closely monitored their training, and this fighting tradition clearly influenced the further development of his weapons. Ichi no tachi Morihei Ueshibu is almost identical to ichi no tachi in Kashima Shinto ryu and the similarities are in other kumitachi.
To be continued