Nakajima Aircraft Company

The Nakajima Aircraft Company was Japan's largest aircraft manufacturer during World War II, responsible for producing more aircraft than any other Japanese company. It grew from the Aircraft Research Institute founded in May 1917 at Ojima and Ōta, Gunma Prefecture, by Nakajima Chikuhei, a former naval engineer officer who believed aircraft should be built by private industry. Supported by Army and Navy orders, the firm was incorporated as Nakajima Aircraft Co., Ltd. in December 1931. Nakajima himself entered politics and served as Railway Minister from 1937 to 1939.

Its three main works were Ōta (Army airframes) and Koizumi (Navy airframes) in Gunma and Musashino in Tokyo (engines), with further plants at Handa, Utsunomiya and Ōmiya. Its products included the Army's Ki-27, Ki-43 Hayabusa and Ki-84 Hayate fighters, the Navy's B5N and B6N Tenzan torpedo bombers, and the Sakae engine that powered the famous Mitsubishi A6M Zero, followed by the Homare; Nakajima also built more than half of all Zeros under licence. Totals differ by source: Japanese accounts give 29,925 airframes up to August 1945, while other statistics put the figure at about 26,000.

Rapid expansion depended on mass mobilisation. Conscripted workers, students and the Women's Volunteer Corps were concentrated around Ōta and Koizumi, and Korean labourers were used to dig the underground dispersal plants of the last year of the war, such as those at Yoshimi in Saitama and Ōya in Tochigi. The company's main factories in Ota and Musashino were primary targets of American strategic bombing: the Musashino works was the first target of B-29s flying from the Marianas, on November 24, 1944, and was struck repeatedly by B-29s and carrier aircraft, while Ōta and Koizumi were heavily damaged from February 1945. On April 1, 1945 the company was nationalised as the First Munitions Arsenal.

After the surrender it was renamed Fuji Sangyō, designated for zaibatsu dissolution by GHQ and split into twelve companies in 1950. Five of them founded Fuji Heavy Industries in 1953, known for Subaru cars and renamed Subaru Corporation in 2017; another line, through Fuji Precision Industries, became Prince Motor Company and merged with Nissan in 1966. Nakajima Chikuhei was named a Class A war crimes suspect but never tried and died in 1949. The Musashino works site is now Musashino Chūō Park, and buildings of the former head office survive in Ōta.