The Imperial Japanese Army had always placed a high priority on the use of unconventional military tactics. From before the time of the First Sino-Japanese War, Japanese operatives, posing as businessmen, Buddhist missionaries in China, Manchuria and Russia established detailed intelligence networks for production of maps, recruiting local support, and gathering information on opposing forces. Japanese spies would often seek to be recruited as personal servants to foreign officers or as ordinary laborers for construction projects on foreign military works. Such activities fell under the oversight of the 2nd Section of the Imperial Japanese Army General Staff Office.
In July 1938, after a number of attempts to penetrate the military of the Soviet Union had failed, and efforts to recruit White Russian had failed, Army leadership felt that a more "systematic" approach to the training of intelligence operatives was required. Lt. Col. Shun Akigusa（秋草 俊）was instructed to organize the curriculum of a special training school, to be located in the 4th district of Nakano, Tokyo. The sign on the school read "Army Correspondence Research Center" to make the public believe that the school was focused on correspondence and not top secret training
The Nakano School was initially focused on Russia, teaching primarily Russian as a foreign language. In 1940, administration of the school was handed over to Lt. Col. Masao Ueda（上田昌雄）, who in 1938 had provided considerable intelligence on Russia from his post as military attaché (a common position for Nakano graduates) in Poland.
After the attack on Pearl Harbor, and the start of World War II, the Nakano School changed its focus to southern targets. After the firebombing of Tokyo, it was relocated to Tomioka-machi, Gunma prefecture.
A small school, over its history, the Nakano School had over 2500 graduates, who were trained in a variety of subject matters related to counterintelligence, military intelligence, covert operations, sabotage, foreign languages, and aikido, along with unconventional military techniques in general such as guerrilla warfare. Extended courses were provided on a wide variety of topics including philosophy, history, current events, martial arts, propaganda, and various facets of covert action.
While small, its graduates occasionally had dramatic successes, such as the intact capture of oil facilities in Palembang, Netherlands East Indies, by Nakano School-trained paratroopers. Nakano graduates were also very active in Burma, India, and Okinawa campaigns.
F Kikan, I Kikan and Minami Kikan(ja) were heavily staffed with Nakano graduates. F- Kikan and I Kikan were directed against British India, and was instrumental in forming the Indian National Army and supporting the Azad Hind movement in Japanese-occupied Malaya and Singapore. It also worked with Indonesian nationalists seeking the independence of the Netherlands East Indies Its efforts to promote anti-British and anti-Dutch movements lasted past the end of the war, and played a role in the independence of India and Indonesia.
In China, one Nakano School operation was the unsuccessful attempt to weaken China's Nationalist government by introducing large quantities of forged Chinese currency using stolen printing plates from Hong Kong.
Towards the end of the war, graduates of the Nakano School expanded their activities within Japan itself, where their training in guerilla warfare were needed to help organize civilian resistance against the prospective American invasion of the Japanese home islands.
Although the Nakano School was abolished at the end of World War II with the surrender of Japan, many graduates continued to play significant roles in Japan's military intelligence hierarchy and the wider business community, a result of a general deal between the head of Japanese intelligence, Lieutenant General Seizo Arisue and General MacArthur (who wanted the Japanese intelligence on the Soviet Union)
Nakano School graduate Second Lieutenant Hiroo Onoda did not surrender until 1974 on Lubang Island in the Philippines. Nakano School graduate Second Lieutenant Kikuo Tanimoto volunteered for the Vietnam Independence War as an adviser in the Quang Ngai Army Academy (Trường Lục quân trung học Quảng Ngãi).
The Nakano School has also been the subject of a number of popular fiction movies, including:
- Rikugun Nakano Gakko: Mitsumei ("Nakano Army School: Top Secret Command") (1967)
- Rikugun Nakano gakko: Kaisen zenya ("Army Nakano School: War Broke Out Last Night") (1968)
- Rikugun Nakano gakko: Kumoichigô shirei ("Army Nakano School: Cloud #1 Directive Japan") (1966)
- Deacon, Richard (1986). A History of the Japanese Secret Service. Berkley Publishing Company. ISBN 0-425-07458-7.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Lebra, Joyce C. (1971). Japanese trained Armies in South-East Asia. Columbia University Press. ISBN 0-231-03995-6.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Fay, Peter W. (1993). The Forgotten Army: India's Armed Struggle for Independence, 1942-1945. University of Michigan Press. ISBN 0-472-08342-2.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Fujiwara, Iwaichi (1983). F. Kikan: Japanese Army Intelligence Operations in Southeast Asia During World War II. Heinemann. ISBN 962-225-072-6.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Mercado, Stephen C. (2002). The Shadow Warriors of Nakano: A History of the Imperial Japanese Army's Elite Intelligence School. Potomac Books Inc. ISBN 1-57488-443-3.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Latimer, Jon (2004). Burma: The Forgotten War. ISBN 978-0-7195-6576-2.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Rikugun Nakano Gakko no Zenbou ("Portrait of the Army Nakano School"), Kato Masao. Tokyo: Tendensha, 1998.
- Nakano Koyukai, ed., Rikugun Nakano Gakko Army Nakano School (Tokyo: Nakano Koyukai, 1978), 176, and Moore, "Open Sources", 104.
- Louis Allen, "The Nakano School", Japan Society Proceedings, 10, 1985, 9-15
- Deacon, A History of the Japanese Secret Service
- Mercado, Nakano, The Shadow Warriors. Pp.1
- See Allen 1987
- Interview with Gozo Shioda
- "Nakano agents and the Japanese forces in New Guinea, 1942-1945." 01-SEP-04, Sabretache. Richmond, Keith 
- Mercado, Nakano, The Shadow Warriors. Pp.40
- Fujiwara, F. Kikan: Japanese Army Intelligence Operations in Southeast Asia During World War 11
- Lebra, Japanese trained Armies in South-East Asia
- Fay, The Forgotten Army: India's Armed Struggle for Independence, 1942-1945.
- Latimer, Burma: The Forgotten War
- "Chūkoku shihei gizō jiken no zenshō" ("The forgery of Chinese paper currency"), Yoshimasa Okada. pages 42-51, October 1980 Rekishi to jinbutsu
- See Boyd 2003
- "Here the author offers a rich description of how the chief of Japanese military intelligence, Arisue Seizo, used his information about the Soviet Union as a bargaining chip with MacArthur's intelligence forces. The result was a special intelligence partnership that had considerable relevance during the early rounds of the Cold War. In all likelihood, this particular Japanese-American cooperation was much more admissible than the initial affair American authorities had with Japanese biological warfare specialists." from "The Shadow Warriors of Nakano: A History of the Imperial Japanese Army's Elite Intelligence School" by Stephen C. Mercado. Review author: Carl Boyd in The Journal of Military History, Vol. 67, No. 1. (Jan., 2003), pp. 274-275. http://links.jstor.org/sici?sici=0899-3718%28200301%2967%3A1%3C274%3ATSWONA%3E2.0.CO%3B2-C
- "ベトナム独立戦争参加日本人の事跡に基づく日越のあり方に関する研究" (PDF). 井川 一久. Tokyo foundation. October 2005. Retrieved 2010-06-10.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- "日越関係発展の方途を探る研究 ヴェトナム独立戦争参加日本人―その実態と日越両国にとっての歴史的意味―" (PDF). 井川 一久. Tokyo foundation. May 2006. Retrieved 2010-06-10.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>