In 1937 the Japanese Imperial Army ordered a fast and light bomber from Kawasaki Heavy Industries with some very impressive performance figures. This aircraft was to be able to combat Russia’s twin-engined light bomber SB-2, which was then in operation in China. Maneuverability was emphasized throughout the new design and it first flew in July 1939. It met all design specifications and was designated the Type 99 twin-engined light bomber in 1940. A total of 1977 were produced in several types, including Type I, ‘Koh’ Type II and ‘Otsu’ Type II. The Ki48-I was the main Army light bomber used during the war. It was easy to maintain and thus in operational readiness more often than other similar types. It was an excellent Army ground support aircraft that could accurately deliver its bomb load in close proximity to front line troops at low altitudes. Its lack of armor and self-sealing fuel tanks, plus the loss of experienced pilots, made the Lily more vulnerable during the later stages of the war, and by then it was used mostly for night operations.