Minoru Mochizuki Sensei (April 7, 1907 – May 30, 2003) was a renowned Japanese martial artist and the founder of the Yoseikan Dōjō.
Mochizuki began his martial arts training at a very young age and developed an exceptionally broad background in Japanese budō. He studied under some of the most prominent masters of his generation, including Jigorō Kanō, founder of Kodokan Jūdō; Kyūzō Mifune, one of the greatest masters of Jūdō; and Morihei Ueshiba, the founder of Aikidō. He also devoted extensive study to classical martial traditions, particularly Tenshin Shōden Katori Shintō-ryū, as well as Jūjutsu, Kenjutsu, Iaidō, Jōjutsu, Kendō, Karate, and Kobudō.
A direct witness to the development of Aikidō!
One of the most significant chapters of Mochizuki's career was his relationship with Morihei Ueshiba. In 1930, at the recommendation of Jigorō Kanō, Mochizuki was sent to study with Ueshiba. At that time, Ueshiba's art was still deeply rooted in Daitō-ryū Aiki-jūjutsu, and the terminology and technical curriculum that would later become associated with Aikidō were still developing. Mochizuki therefore encountered Ueshiba during a crucial transitional period between the Daitō-ryū tradition and the emerging art that would eventually be known as Aikidō.
Mochizuki rapidly became one of Ueshiba's senior assistants. At the Kobukan Dōjō, he was entrusted with supervising the uchideshi and assisting Ueshiba in teaching. His extensive previous experience in Jūdō and classical martial arts enabled him to absorb Ueshiba's techniques rapidly.
His connection with the Daitō-ryū tradition was particularly significant. In June 1932, Ueshiba presented Mochizuki with two scrolls concerning Daitō-ryū Aiki-jūjutsu, including Hiden Ōgi. The documents bear Ueshiba's name together with the designation identifying him as a student of Takeda Sōkaku, providing important historical evidence of the Daitō-ryū foundation within Ueshiba's early art.
Mochizuki's experience is therefore especially valuable from a historical perspective: he was not simply a later practitioner of an established Aikidō system, but a direct student of Ueshiba during the period in which Ueshiba's martial art was evolving from its Daitō-ryū Aiki-jūjutsu foundations toward what would become modern Aikidō.
He attained high-ranking grades in numerous martial arts, including 10th dan in Aikidō, 9th dan in Jūjutsu, 8th dan in Iaidō, 8th dan in Jūdō, 8th dan in Kobudō, 5th dan in Karate, 5th dan in Jōjutsu, and 5th dan in Kendō.
Through his extensive training, synthesis of different martial traditions, and teaching activities, Mochizuki Sensei played a pioneering role in the development and international dissemination of Japanese martial arts. In particular, his influence in Europe was profound, and he is widely regarded as one of the most important figures in the introduction, development, and transmission of several Japanese martial arts on the continent.