The Relationship Between Yōseikan and Morihei Ueshiba

In the words of Hiroo Mochizuki, here is the story of the birth of Yoseikan Aikido at the hands of Minoru Mochizuki. This excerpt is taken from “The Heir – Interview with Hiroo Mochizuki“, the interview book that deals, among other things, with Minoru Mochizuki’s relationship with Ueshiba and Kano, the two martial giants of the 20th century


“After receiving Kanō sensei’s approval, my father became Ueshiba sensei’s first assistant. Later, he fell ill [a form of pneumonia] and Kanō sensei arranged for him to be admitted to hospital in Tōkyō. Both Ueshiba and Kanō sensei lived in Tōkyō; Kanō sensei had the best hospital in Tōkyō paid for him through the Kōdōkan to ensure that nothing would go wrong. My father was very distraught that Kanō sensei was taking care of him: it didn’t seem right to him because there were many important jūdōka, his superiors in training and rank, and so it was apparent that Kanō sensei considered him an exceptional person. Therefore he apologised to Kanō sensei, left for Shizuoka where our ancestral family home is located, and went to the hospital in Shizuoka. In spite of this, Ueshiba sensei kept him as the head of assistants of his Dōjō for two years.

“Later on, in 1938, once he had recovered, my father left for Inner Mongolia as part of the Japanese political effort in line with the reasons of that period. This departure was due both to his political activism alongside his elder brother Shinpachi, to whom he was very close, and to Ueshiba sensei’s encouragement.

“Manchuria was a defined country even before China was formed. It had ancient links with Japan, and was considered a country where the theory of the ‘Great Sphere of Prosperity’ could be developed. This is why various political and social groups, and even Ueshiba sensei, [1] set out to organise supporters on the ground to support the independence and development of Manchuria. [2]

The Heir
Interview with Hiroo Mochizuki

The Aiki Dialogues #8
by Adriano Amari, Hiroo Mochizuki, Michihito Mochizuki

Hiroo Mochizuki is the heir of a samurai family.
Creator of Yoseikan Budo, he is a world-renowned expert in Japanese martial arts.
Son of the famous teacher Minoru Mochizuki, who is considered a Japanese national treasure and was also a direct student of Jigoro Kano and Morihei Ueshiba, the successor of a line of samurai, Hiroo Mochizuki was inspired by his forefathers combative spirit to create Yoseikan Budo.
He adapted the philosophy, pedagogy and traditional practice of martial arts to a new modern environment, as well as to contemporary combat techniques.
Besides practicing Mixed Martial Arts before people knew what MMA were, Hiroo Mochizuki has one of the most impressive records in the martial world.


“Thus, by this time they had separated, my father was in China while Ueshiba sensei had stayed in Japan and continued to teach in his Dōjō, even though he travelled to Manchuria on several occasions.
“After the war, we lost the first Yōseikan Dōjō because of the bombings; Ueshiba sensei was still in Tōkyō. My father often travelled to Tōkyō and met with Ueshiba sensei. On the other hand, before the war Ueshiba sensei often came to our Dōjō in Shizuoka. After the war the Dōjō was no longer there, so we invited him to Mochimune, [3] then a small village of farmers and fishermen southwest of Shizuoka, where he had opened a medical practice as a kinesiologist. [4]

“My father lived in Mochimune for a while, working as a kinesiologist. Then he decided to build another Dōjō in Shizuoka with the money he had earned, so the second Dōjō was born; at the same time he continued to practice kinesiology. However, because of this new building, all patients were now seen and treated at the Dōjō, and he was sleeping there at that time. Ueshiba sensei often came to this new Dōjō, my father gave him massages and they trained together. There was no kitchen, so they would go outside, make a charcoal fire to cook, and eat rice and other food there, sitting by the side of the fire. They would both lie down on the mat.

Shimbuden, Kenkoku University, Manchuria (1942. Morihei Ueshiba with Kenji Tomiki at his side and Hideo Ohba behind him

“Then, after a year, my father built a separate studio in front of the Dōjō.”

[AA] “I’ve heard some interesting stories about the ‘birth of the First Yōseikan Dōjō’, Sensei! Would you mind telling us a little about that?”

[HM] “Sure, why not? The first Dōjō, the one destroyed by American bombings, was in the Hitoyado-chō district of Shizuoka. The second, built after World War II, was in Daiku-chō. It was not in the same place, but not too far away, about a fifteen minute walk.

“The first Dōjō was built by his older brother, Shinpachi, who then accompanied him to Mongolia. He was a dentist [5] and had earned a lot of money. So he wanted to make sure his brother stayed in Shizuoka and had peace of mind. My father was kind of crazy about Jūdō: while recovering from pneumonia, he had repeatedly escaped from the hospital to train at the Shizuoka Police Dōjō. One day Shinpachi discovered him and scolded him, saying, ‘What are you doing? If you keep this up, you might die!’

“My father was too engrossed in Jūdō, so his older brother wanted to keep an eye on him and prevent him from returning to Tōkyō and continuing to exceed in his training.

“So he built this first Dōjō to keep him in Shizuoka. Ueshiba sensei came to the inauguration with all his students, who were prominent figures in the political world and in the armed forces, generals and admirals, very important military politicians at that time.

“They came because Ueshiba sensei regarded my father very highly, he saw him as a son [6], and he wanted to honour him by bringing all these important people to the inauguration. This was something that Ueshiba sensei did only for my father.”

[Mitchi Mochizuki] “You told me that Ueshiba sensei used to come to the Dōjō in Shizuoka, and that grandfather used to arrange seminars for him.”

[HM] ”Even before the war Ueshiba sensei used to visit and my father organised seminars for him at his Dōjō and at the municipal Dōjō.

“Later, at the time of the second Dōjō, he would go to Tōkyō to see Ueshiba sensei and he would come to Shizuoka to visit him. My father was very busy with his work as a kinesiologist, whereas Ueshiba sensei was quite free and came to see him often. He always wanted him to be his assistant, but in time he realised that this was not possible because of my father’s work and family commitments.

“So Ueshiba Sensei lived in Tōkyō and my father used to go to his Dōjō, the Kobukan, to visit him. On the other hand Ō Sensei used to come to Shizuoka where my father organised seminars. He introduced Ueshiba sensei not to his young students, but to the leading people of the city of Shizuoka, and for this purpose he invited a large number of people to the hall attached to the main Shintō Shrine. Ueshiba sensei used to give long speeches and at the same time presented techniques. People came to attend the seminar, but there were no jūdoka or aikidōka among them, so we, the young people of the Dōjō, went to assist Ueshiba sensei, who showed techniques suitable for beginners. Sometimes he came with Saitō and Yamaguchi sensei, and in this case we took advantage to practice with them. These were not really seminars with Ueshiba sensei, rather he made Saitō sensei work and showed a few things from time to time, not too challenging for the young students, who were all Jūdō competitors or who had been practicing Aikidō for many years. We fell well, we had no problems doing Aikidō, for us jūdōka it was quite easy.

The inauguration of the first Dōjō Yōseikan, in Shizuoka, on 3 November 1931. In the centre, to the left of the Kamidana, in the front row Morihei Ueshiba, to his right General Miura. To the right of the Kamidana Admiral Takeshita and Minoru Mochizuki. In the second row, third from the right, Kenshiro Abbe.

“Ueshiba sensei’s last visit to Shizuoka – I being in Japan – was in 1962. I had returned from France, my first trip back, in 1959 and would leave again in 1963. In 1962 we had a party for the Yōseikan Dōjō, and it was held in a theatre where two thousand people could sit. The theatre was fully filled. As on other occasions, my father had invited Shizuoka’s most important personalities in martial arts (all disciplines included, Jūdō, Kendō and others), as well as politicians, Shintō and Buddhist ministers. We did a demonstration and this was the last time I saw Ueshiba sensei, who had come for the occasion. This is where I met Tamura sensei for the first time. He then also moved to France for the Aikikai. At that time, he was training with Ueshiba sensei’s son Kisshomaru in Tōkyō.

“After World War II, Ueshiba sensei had moved to live in Iwama, and occasionally would go to Tōkyō. So from Iwama he had come down to Tōkyō and asked his son to ‘lend’ Tamura sensei to accompany him to Shizuoka.”

Read the full book interview here

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Minoru Mochizuki


[1] With the Ōmoto- kyō in 1924 and again thereafter.
[2] By the end of World War I, ‘Outer Mongolia’, corresponding to the present-day state of Mongolia, had broken away from China and become a nation in its own right, virtually a protectorate of Bolshevik Russia. ‘Inner Mongolia’, as distinct from Outer Mongolia, was a large swathe of territory along its eastern and southern borders. It had fallen into a phase of anarchy where bands of stragglers and new warlord’ ruled. With part of this strip and by adding territories between it and Korea, the Japanese created the Manchu-Kuo empire/protectorate in 1931.
According to Hiroo Mochizuki sensei: “In Manchuria and Inner Mongolia there were important contacts for Japan and a very popular political movement wanted to make Manchuria an independent country within the Japanese ‘sphere of prosperity’. These countries, Inner Mongolia, Outer Mongolia and Manchuria, were a very vague place internationally. The idea of Japanese policy was to create a state and make it official internationally and so they did a coup on Inner Mongolia and the Chinese part, Manchuria, and put the last Chinese emperor in charge of Manchuria. My father and uncle had this vision, to help independence from China, Russia and Outer Mongolia, and to develop the country”.
[3] In Mochimune lived the family of Minoru sensei’s wife, the Shinmura, descendants of the ancient Takeda samurai. For this clan, in the days of Shingen Takeda, they guarded the nearby Mochimune castle on Mount Shiroyama.
[4] Minoru Mochizuki sensei received full training as a kinesiologist-osteopath at the Kōdōkan. It was a program established by Kanō sensei himself, called ‘Jūdō Seifuku-shi’, made official by a state diploma. The aim of the program was to give Jūdō instructors greater thoroughness and a professional outlet parallel to their martial activity.
[5] The Mochizuki were six brothers and six sisters, Minoru being the fifth son. The eldest son Kane-Ichi was a regional Sumō champion, Sadao was an expert in Kyudō. The youngest, Sue-Hichi, was also a Jūdō and Aikidō instructor.
[6] Shortly after the opening of the Dōjō in Shizuoka, Ueshiba sensei sent – as was the custom – Admiral Takeshita to propose to Minoru to marry his daughter and be adopted into the Ueshiba family, becoming in fact the heir of the school. Mochizuki sensei declined the invitation mainly because he would have had to leave Kanō sensei and Jūdō.