He incorporated Aikido, Jui-Jitsu techniques (Goshin Jitsu) and Kobudo (weapons) as part of the Tenshinkan Karate system, forming a complete martial art.  His concepts are unique since they are  based on Tai Sabaki (avoidance) and Ashi Sabaki (leg shifting).

Kancho Mamoru Miwa was born in the North Region of Japan. His family tree has a background and tradition linked with the Samurai. His father was a Shogunate Samurai and continued the tradition and principles of the Samurai; and Mamoru Miwa was trained in the principles of Bushido, as was required of him to continue the family tradition of Bushido (Samurai). Thus, at the age of four, Mamoru Miwa’s parents started to coach him in Martial Arts. Mamoru Miwa trained in various Martial Arts, namely Karate, Jui-Jitsu, Aikido and Kobudo (Karate and Goshin Jitsu were his favourites).

Mamoru Miwa studied Karate with Gichin Funakoshi Sensei, with heart and soul, and practised with such total sincerity and dedication, that master Gichin Funakoshi gave him the pet name of Tenshin, which when translated means The Sincere (True) One.