1. Early Life and Education
Masaichi Niimi was born on February 4, 1887, in what is now Asakita Ward, Hiroshima City, Hiroshima Prefecture, as the second son to a family engaged in farming and soy sauce production. His father was Niimi Sengoro. He attended Hiroshima Prefectural Tadami Middle School before entering the Imperial Japanese Naval Academy on December 2, 1905. He graduated from the academy's 36th class on November 21, 1908, ranking 14th out of 191 cadets upon graduation, having entered as 35th out of 200. Among his classmates was Mito Haruzo, who also became a Vice Admiral. Niimi's wife, Sumiko, was the sister of Admiral Seizo Kobayashi.
2. Naval Career
Niimi's naval career progressed steadily through various assignments, specialized training, and increasing responsibilities, culminating in high-ranking commands during World War II.
2.1. Naval Academy and Initial Assignments
After graduating from the Imperial Japanese Naval Academy, Niimi was commissioned as a midshipman on November 21, 1908. He began his service aboard the armored cruiser Aso and later the armored cruiser Izumo. On January 15, 1910, he was commissioned an ensign, and on December 1, 1911, he was promoted to sub-lieutenant. His initial assignments included posts at the Sasebo Naval District and the Sasebo Naval Barracks. He participated in several distant training voyages, including one from March 14 to August 7, 1909, visiting locations such as Honolulu, Hilo, San Francisco, Esquimalt, Vancouver, Tacoma, Seattle, Hakodate, and Ōminato. Another voyage from November 25, 1911, to March 28, 1912, took him to Guam, Suva, Auckland, Sydney, Townsville, Batavia, Singapore, Manila, and Olongapo City.
2.2. Specialized Training and Professional Development
Niimi pursued extensive specialized training early in his career. In 1910, he attended naval artillery and torpedo school. He was assigned back to the Aso on April 20, 1911, serving as a midshipman instructor, followed by service on the destroyer Yayoi from July 5, 1912. On December 1, 1913, he became an Otsu-class student at the Naval War College (Japan). He completed the 13th class of the Naval Artillery School's advanced course on November 26, 1914. Promoted to lieutenant on December 1, 1914, he served on the battleship Katori, the battlecruiser Ibuki, the battleship Kawachi, and the destroyer Umikaze. From April 1, 1917, he served as an instructor and division officer at the Naval Artillery School. He entered the Naval War College's A-class (17th class) on December 1, 1917, specializing in naval artillery, and graduated fourth in his class of 24 on November 26, 1919. He then became chief gunnery officer on the battleship Ise. On December 1, 1920, he was promoted to lieutenant commander and returned to the Naval Artillery School as an instructor. From December 1, 1923, to December 1, 1925, he served as a naval attaché assistant at the Japanese Embassy in the United Kingdom, during which time he also studied international law at Oxford University. He was promoted to commander on December 1, 1924.
2.3. Command and Staff Roles
Upon his return to Japan, Niimi was assigned as executive officer on the light cruiser Kuma on March 20, 1926. From December 1, 1926, he served as an instructor at the Naval War College. He was promoted to captain on November 30, 1929, and concurrently served as a military science instructor at the Army War College (Japan) from November 27, 1929. After a period attached to the Yokosuka Naval District from December 1, 1930, he received his first command on April 1, 1931: the light cruiser Ōi. On October 15, 1931, he became captain of the training armored cruiser Yakumo. He led a training fleet on a distant voyage from March 6 to July 26, 1933, visiting Seattle, Tacoma, Esquimalt, Vancouver, San Francisco, Los Angeles, Acapulco, Balboa, Honolulu, Jaluit, Truk, Saipan, and Palau. On November 15, 1933, he took command of the heavy cruiser Maya. He returned to the Naval War College as an instructor on November 15, 1934.
2.4. High-Ranking Commands and World War II Service
Niimi was promoted to rear admiral on November 15, 1935, and appointed Chief of Staff of the Kure Naval District. From April 1, 1936, he served as Chief of Staff of the IJN 2nd Fleet. On January 8, 1937, he accompanied Prince Chichibu and his wife to England for the Coronation Ceremonies of King George VI, departing on March 18 and arriving in England on April 12. After the ceremonies, he visited France, Germany, and the United States, returning to Japan on July 28. From December 1, 1937, he served as Director of the Naval Education Bureau. He was further promoted to vice admiral and appointed Commandant of the Imperial Japanese Naval Academy on November 15, 1939.
On April 4, 1941, Niimi assumed command of the 2nd China Expeditionary Fleet. In this role, he was responsible for the naval component of the invasion of Hong Kong, which involved primarily blockading Hong Kong harbor with small patrol craft and a couple of light cruisers. He nominally shared the position of Head of Japanese Occupation Forces in Hong Kong with General Takashi Sakai, but his authority was limited to offshore areas. On July 14, 1942, he became Commander in Chief of the Maizuru Naval District. He retired from active service on March 15, 1944, and was placed on the reserve list on March 20, 1944. On March 25, 1944, he became Vice Chairman and Central Headquarters Chief of the Dainippon Gakuto Kaiyo Kyoiku Shinkokai, resigning on March 1, 1946. He was provisionally designated for Public Office Purge on November 28, 1947.
3. Strategic Thought and Analysis
Masaichi Niimi was recognized as one of the Imperial Japanese Navy's leading intellectuals, particularly for his expertise in naval artillery and his strong grasp of English, having studied international law at Oxford University. His strategic insights proved remarkably prescient regarding the nature of future warfare.
During his tenure as naval attaché assistant in the United Kingdom from 1923 to 1925, he conducted extensive research into the history of World War I. Upon his return to Japan, he submitted two crucial reports to the Imperial Japanese Navy General Staff: "Opinion Paper on the Improvement of Naval Central Military Command Organization" and "Opinion Paper on Protracted Warfare." In these documents, Niimi argued that the next global conflict would be a total war and that the concept of a decisive fleet battle (艦隊決戦Kantai KessenJapanese) would not materialize. He emphasized the necessity of the Imperial Headquarters functioning as a unified political-military body and, most critically, highlighted the urgent need for measures to defend maritime traffic lines. Although his views were initially considered unconventional by his peers, the subsequent course of the Pacific War ultimately validated his predictions regarding total war and the vital importance of sea lane defense.
As a Naval War College instructor for a total of five years, Niimi consistently advocated for his strategic principles. While serving as Director of the Naval Education Bureau, he attempted to establish a Naval Defense School to implement comprehensive measures for maritime traffic defense. However, this initiative faced opposition from the Naval Affairs Bureau, led by Shigeyoshi Inoue, and ultimately resulted in the establishment of only the Naval Mine School. Although Niimi and Inoue shared a pro-Anglo-American stance, they held differing views on the curriculum at the Naval War College and the unification of the engineering and line officer branches.
Niimi also held strong convictions regarding international relations. Even after the signing of the Anti-Comintern Pact between Japan and Germany, he believed that Britain desired an alliance with Japan, a conclusion he drew from the favorable treatment extended to Prince Chichibu during the coronation of King George VI. He further argued that given the immense national power demonstrated by the United States in World War I, Japan should align itself with the US and UK and avoid further rapprochement with Germany and Italy. Despite his persistent warnings, his advice was not heeded.
4. Post-War Activities
After his retirement from active service in 1944 and the conclusion of World War II, Masaichi Niimi remained dedicated to naval affairs and historical research. He served as a special lecturer for the Maritime Self-Defense Force Staff College, contributing his extensive experience and strategic insights to the new generation of naval officers. He also became the supreme advisor for the "Naval Reflection Meeting" (海軍反省会Kaigun HanseikaiJapanese), a re-established organization of former naval officers known as the Suikokai, where he continued to share his perspectives on the Imperial Japanese Navy's history and lessons learned.
Niimi placed great importance on the study of war history. From the age of 82 to 84, he authored the comprehensive work, History of World War II War Leadership (第二次世界大戦戦争指導史Dainiji Sekai Taisen Sensō ShidōshiJapanese). This significant book was eventually published when he was 97 years old. The work was presented to Emperor Showa, who expressed pleasure at its publication, and it was also gifted to Crown Prince Akihito.
5. Personal Life and Character
Masaichi Niimi was known for his mild and non-confrontational personality. He preferred not to impose his opinions forcefully and generally avoided disputes with others. Despite his high rank and strategic acumen, he was described as a person who did not insist on his own views. This temperament earned him the respect and affection of many of his subordinates and peers, including Atsushi Oi, who admired him as the longest-living admiral of the navy. Niimi's remarkable longevity, living to the age of 106, also contributed to his symbolic status as a revered elder statesman among former naval officers.
6. Death and Legacy
Masaichi Niimi died on April 2, 1993, at the extraordinary age of 106 years. At the time of his death, he held the unique distinction of being the last surviving vice-admiral of the Imperial Japanese Navy. His legacy is primarily defined by his profound strategic insights, particularly his early and accurate predictions regarding the nature of total war and the critical importance of sea lane defense, which were ultimately validated by the course of the Pacific War. His post-war dedication to historical research and his efforts to share his knowledge with the Maritime Self-Defense Force further cemented his role as a significant figure in Japanese naval history.
7. Awards and Honors
Masaichi Niimi received several official decorations and held various court ranks throughout his distinguished career, and also authored significant works on naval history.
- Order of the Sacred Treasure, 1st Class (July 8, 1942)
- Court Ranks:
- Junior Eighth Rank (March 22, 1910)
- Junior Seventh Rank (February 10, 1915)
7.1. Major Writings
- History of World War II War Leadership (第二次世界大戦戦争指導史Dainiji Sekai Taisen Sensō ShidōshiJapanese), Hara Shobo, 1984. ISBN 4-562-01516-0.
- The Common Sense of the Japanese Navy: Admiral Masaichi Niimi - Autobiography and Reminiscences (日本海軍の良識 提督 新見政一 自伝と追想Nihon Kaigun no Ryoshiki Teitoku Niimi Masaichi: Jiden to TsuitōJapanese), edited by Teitoku Niimi Masaichi Kankokai, Hara Shobo, 1995. ISBN 4-562-02696-0.