09/09/2025
Tetsuo Hoshi demonstrating a "new" martial art, "Kobu" (皇武 / "Imperial Martial Arts") at the Kodokan in 1940. Actually, this is Morihei Ueshiba's art, "Kobu" being after Morihei Ueshiba's "Kobukan" dojo.
Tetsuo Hoshi was a high ranking Judo practitioner before meeting Morihei Ueshiba and becoming his student. He was also, originally, the Judo instructor of Tsutomu Yukawa, one of Morihei Ueshiba's top students who was once the presumed successor to Ueshiba's art before being knifed in a bar fight.
John Stevens notes Hoshi as a Kodokan 6th Dan in "The Way of Judo: A Portrait of Jigoro Kano and His Students", but this article notes that he was a 5th Dan. Stevens also claims that he "returned his ranks" to the Kodokan after meeting Morihei Ueshiba, but there appears to be no record of this.
What is true is that Tetsuo Hoshi was so enamored of Morihei Ueshiba and his art that he changed his first name to "Aiki", and it is under that name that he appears in military records - Lieutenant Aiki Hoshi was executed by hanging in Singapore for war crimes committed during his time on the Burma-Siam railway - yes, the same one that appears in the Oscar winning movie "The Bridge Over the River Kwai".
The explanatory text is quite interesting, and repeats the language that Morihei Ueshiba himself used, but fails to give any mention to Morihei Ueshiba (or Sokaku Takeda, since there are some clear references to the Daito-ryu origin mythology):
"Five-dan rank holder Hoshi Tetsuo, who has spent many years researching the 'Imperial Japanese Martial Arts' passed down from the age of the gods, has now completed his research. On January 18, at 8:00 AM, he will present the techniques under the name 'Kobu' at the Kodokan.
The distinctive feature of this Kobu is its 'empty-handed' style, where one can easily subdue an opponent, even if the opponent is armed with a sword or spear. This is a true 'unarmed victory' style.
The Kodokan director, Nango (*this was Nango Jiro, the second director of the Kodokan), and other high-ranking practitioners were present as Hoshi demonstrated various techniques. The foreign judo researcher, a British man named Leggett (*this was Trevor Leggett, who began Judo at the Budokwai in London, and held a Kodokan 6th Dan), and a staff member from the British Embassy named O'Neil were among those who became his partners. Despite their large physiques, they were easily twisted and thrown to the ground, their eyes wide with surprise.
According to Hoshi, 'Kobu' is the origin of all martial arts, an ancient Japanese martial art that was deeply researched. He explained that the five elements are born from yin and yang, all things are created from the five elements, and Kobu expresses these principles through the body. It is a way of embodying the principles of heaven and earth, yin and yang, from which countless techniques naturally arise. When an opponent attacks, the body evades the strike and the hands move in to apply leverage and a reverse hold on the opponent's arm."
Tetsuo Hoshi is also mentioned by Sadao Takaoka, who had the opportunity to be taught by both him and Tsutomu Yukawa, in "Aikido Shihan Sadao Takaoka – Meeting O-Sensei":
https://www.aikidosangenkai.org/blog/sadao-takaoka-meeting-osensei/
