Also known as

Description

Japanese judoka and jujutsuka. Founder of the Budokwai (1918), known as the 'Father of British Judo.' Studied Tenjin Shinyo-ryu under Nobushige Tago, later Shin-Shin-Ryu under Yamada Nobukatsu and Akishima-Ryu under Akishima Tsunejiro. Converted to Kodokan Judo in 1920 under Jigoro Kano. Co-founded the British Judo Association (1948) and European Judo Union (1948). Author of 'My Study of Judo' (1960). Held 8th dan Kodokan.

Teachers (3)

• 
  Tago Nobushige

  linkTenjin Shin'yō-ryū 3

  Confirmed

  Documented in Gunji Koizumi's own autobiographical account in 'My Study of Judo' (1960)

  sports_kabaddiSeibukan badge (1901)

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  2 sources

  fact_check

  Documented in Gunji Koizumi's own autobiographical account in 'My Study of Judo' (1960)

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "Moving to Tokyo, and under the stress of the usual schoolboy feuds, I took up Tenshin-Shinyo-Ryu Ju Jutso under NOBUSHIGE TAGO, who was quite an impressive figure with a long grey beard"

  — Koizumi, Gunji. (1960). My Study of Judo - The Principles And The Technical Fundamentalslinkinfo

  "In 1901, he started practising jujutsu under Tago Nobushige at the Tenjin Shinyo-ryu."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo
• Ya
  Yamada Nobukatsu

  (1904-1904)

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  2 sources

  fact_check

  Documented in Gunji Koizumi's autobiographical account and Wikipedia

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "In 1904, in Fusan, Korea, I attended the Kenjutsu and Ju JUTSU school conducted by an ex-samurai of the Owari clan, Sensei NOBUKATSU YAMADA and learned the techniques of SHIN-SHIN-RYU, JU JUTSU and KATSU."

  — Koizumi, Gunji. (1960). My Study of Judo - The Principles And The Technical Fundamentalslinkinfo

  "In 1904, he trained under Yamada Nobukatsu, a former samurai."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo
• Ak
  Akishima Tsunejiro

  (1905-1906)

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  2 sources

  fact_check

  Documented in Gunji Koizumi's autobiographical account and Wikipedia

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "During a four months' stay in Singapore from November 1905 to February 1906, I helped Sensei T. Akishima in conduct of his Ju Jutsu school and was taught the 144 techniques of AKISHIMA-RYU and KATSU."

  — Koizumi, Gunji. (1960). My Study of Judo - The Principles And The Technical Fundamentalslinkinfo

  "While in Singapore in 1905, he trained under Tsunejiro Akishima."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo

Ranks (5)

• linkKōdōkan Jūdō

  military_tech2 dan 2

  Probable

  Awarded by Jigoro Kano on his 1920 visit to the Budokwai, documented in Wikipedia and academic sources

  Dan-Kyu System (1920)

  granted by Kanō Jigorō, Kodokan

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  2 sources

  fact_check

  Awarded by Jigoro Kano on his 1920 visit to the Budokwai, documented in Wikipedia and academic sources

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "In July 1920, Jigoro Kano, founder of the Kodokan, visited the Budokwai while on his way to the Olympic Games in Antwerp. After some discussion, Koizumi and Yukio Tani agreed to change to the judo system, and Kano awarded them 2nd dan judo certifications."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo

  "In 1920 Jigoro Kano visited the Budokwai, on his way to the 1920 Olympic Games as Head of the Japanese Delegation"

  — Callan, Mike. (2011). Gunji Koizumi: The Father of European Judolinkinfo

  military_tech4 dan 2

  Probable

  Documented in Wikipedia and Budokwai historical sources

  Dan-Kyu System (1932)

  granted by Kodokan

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  1 source

  fact_check

  Documented in Wikipedia and Budokwai historical sources

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "In 1932, he was promoted to 4th dan in judo."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo

  military_tech6 dan2

  Probable

  Documented in Wikipedia and academic sources

  Dan-Kyu System (1948)

  granted by Kodokan

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  1 source

  fact_check

  Documented in Wikipedia and academic sources

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "In 1948, Koizumi was promoted to 6th dan in judo."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo

  military_tech7 dan2

  Probable

  Documented in Wikipedia and academic sources

  Dan-Kyu System (1951)

  granted by Kodokan

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  1 source

  fact_check

  Documented in Wikipedia and academic sources

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "In 1951, he attained the rank of 7th dan in judo."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo

  military_tech8 dan 2

  Probable

  Awarded 17 November 1962 per Japanese sources (Kudo 1965); confirmed by Black Belt Magazine Nov 1965

  Dan-Kyu System (1962-11-17)

  granted by Kodokan

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  2 sources

  fact_check

  Awarded 17 November 1962 per Japanese sources (Kudo 1965); confirmed by Black Belt Magazine Nov 1965

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "1962年11月17日付で8段位を拝受"

  — 小泉軍治 - Wikipedia (Japanese). Wikipedia (Japanese) linkinfo

  "He held the rank of 8th dan in judo."

  — Gunji Koizumi - Wikipedia (English). Wikipedia (English)linkinfo

Students (2)

• 
  Moshé Feldenkrais

  linkKōdōkan Jūdō 2

  Probable

  Feldenkrais's own preface to Higher Judo acknowledges Koizumi as someone he learned a great deal from (primary); de Crée (2013) confirms from the Budokwai dan-rank register that Feldenkrais joined the Budokwai in 1948; FEFNA and Nativ both place him studying judo under Koizumi at the London Budokwai. Probable

  sports_kabaddiBudokwai badge (1948-1950)

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  5 sources

  fact_check

  Feldenkrais's own preface to Higher Judo acknowledges Koizumi as someone he learned a great deal from (primary); de Crée (2013) confirms from the Budokwai dan-rank register that Feldenkrais joined the Budokwai in 1948; FEFNA and Nativ both place him studying judo under Koizumi at the London Budokwai. Probable

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "He took judo classes with Gunji Koizumi at the London Budokwai."

  — Who Was Moshe Feldenkrais?linkinfo

  "After leaving the service in 1945, he moved to London and joined the Budokwai, where he studied judo under the great master G. Koizumi."

  — Moti Nativ. (2017). On Better Judo: Moshe Feldenkrais on Learning, Balance, and Masterylinkinfo

  "Feldenkrais only joined the Budōkwai in 1948, thus well after he had left France and had moved to England."

  — Carl de Crée. (2013). Shōnen Jūdō-no-kata ["Forms of Jūdō for Juveniles"] - an experimental Japanese teaching approach to Jūdō skill acquisition in children considered from a historic-pedagogical perspective - part IIlinkinfo

  "It has been my good fortune to meet Mr. G. Koizumi, from which I have learned a great deal. The clarity of his knowledge is equal to the generosity with which he imparts it"

  — Moshe Feldenkrais; Elizabeth Beringer. (2010). Higher Judo: Groundworkinfo

  "In London he deepened his friendship and judo practice with legendary practitioners Gunji Koizumi and Trevor Leggett."

  — Moshe Feldenkrais; Elizabeth Beringer. (2010). Higher Judo: Groundworkinfo
• 
  Sarah Mayer

  linkKōdōkan Jūdō 3

  Confirmed

  Wikipedia states Mayer first trained in judo by Gunji Koizumi at the Budokwai in the 1920s; Callan/Heffernan/Spenn confirm the ladies' classes were taught by Koizumi at the Budokwai, which Mayer joined in 1926.

  sports_kabaddiBudokwai badge (1926-1933)

  expand_morefact_checkassessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  2 sources

  fact_check

  Wikipedia states Mayer first trained in judo by Gunji Koizumi at the Budokwai in the 1920s; Callan/Heffernan/Spenn confirm the ladies' classes were taught by Koizumi at the Budokwai, which Mayer joined in 1926.

  assessed by FSMverified

  Frederico Muñoz

  Researcher, Martialis

  "Mayer first trained in judo by Gunji Koizumi at the Budokwai in the 1920s."

  — Wikipedia contributors. (2026). Sarah Mayer - Wikipedia (English). Wikipedia (English)linkinfo

  "In 1926, Mayer... first joined the Budokwai as the thirty-first female member. The ladies' classes, at that time, were taught by Koizumi, the founder, and Tani Yukio."

  — Callan, Mike; Heffernan, Conor; Spenn, Amanda. (2018). Women's Jūjutsu and Judo in the Early Twentieth-Century: The Cases of Phoebe Roberts, Edith Garrud, and Sarah Mayer linkinfo

Sources