He was a long time shihan (Teaching Master) of Tenshin Shōden Katori Shintō-ryū bujutsu,[2][3] which he learned as a disciple of the previous teaching master Hayashi Yazaemon (1892-1964) from the time he entered the school in 1942 at the age of 16.

[4] In 1967, when Otake-sensei was 42 years old, he received gokui kaiden, the highest level of attainment in the tradition, and at the same time became the school's teaching master.

[5] He lived and taught in rural location near Narita city, in Chiba Prefecture of Japan.

[6] He authored Strategy and the Art of Peace, as well as an earlier three-volume set of books on the tradition entitled The Deity and the Sword: Katori Shinto-ryu.

He was a member of the Chiba Prefecture Board of Registrars and Appraisers for Muskets and Swords; a position he held since 1979.