The Kawasaki OH-1 (nickname: "Ninja") is a military scout/observation helicopter developed and manufactured by the Kawasaki Aerospace Company. The primary operator is the Japan Ground Self-Defense Force (JGSDF), who originally procured the OH-1 as a domestically produced successor to their existing OH-6D Loach fleet. The OH-1 has the distinction of being the first helicopter to be entirely produced in Japan. In addition to its use as an observation helicopter, it can also be armed to directly participate in combat; such weapons include a limited quantity of air-to-air missiles for self-defense purposes. Several variants of the OH-1 have been proposed, these have included derivatives of the type to serve as an attack helicopter as well as an aborted project to develop a utility helicopter. As of March 2014, a total of 38 OH-1s have entered service with the JGSDF; so far these complement the existing OH-6Ds rather than replace them. In December 2022, the Japanese government decided to replace 33 OH -1, 12 AH-64D, 47 AH-1S, and 26 U-125A with unmanned aerial vehicles. Japan plans to increase its defense budget from 1.24% of GDP in fiscal 2021 to around 2.0% within 10 years, and has decided to retire these helicopters and aircraft as part of an effort to spend its defense budget efficiently. Development Origins During the late 1980s, the JGSDF developed a requirement for a new scout/observation helicopter to replace its Kawasaki license-built OH-6Ds, which became the OH-X programme. In June 1989, the JGSDF announced their intention to pursue the development of the OH-X. Several proposals to meet the OH-X requirement were submitted by Kawasaki, Fuji and Mitsubishi. In 1991, Kawasaki's proposal was selected by the JGSDF's Technical Research and Development Institute as the prime contractor for the OH-X programme. On 18 September 1992, the Kawasaki design formally appointed by the Ministry of Defense as the winner. Kawasaki was made responsible for producing 50 percent of the airframe, as well as coordinating development of the rotor system; the remaining airframe elements were manufactured by Mitsubishi and Fuji. Development was formally launched in October 1992. In early 1996, the first OH-1 prototype was rolled out. On 6 August 1996, the first of four OH-1 prototypes (designated XOH-1) performed the type's maiden flight. All four prototypes were flying by March 1997. The four prototypes were delivered to the Japanese Defence Agency for service testing from June to August 1997. By April 1998,