The Navy ordered development as the 17-shi in September 1942, and the first test flight took place in September 1943. It entered service in January 1945. The Q1W carried two low-power engines, allowing for long periods of low-speed flight, and was the first purpose-designed anti-submarine warfare aircraft in the world. A total of 143 examples were produced.
The KyushuQ1W Tokai (東海 "Eastern Sea"), was a land-based anti-submarine patrol bomber aircraft developed for the Imperial Japanese Navy in World War II.
The design may have been derived from the German Junkers Ju 88 medium bomber, the Japanese Navy having received some examples for technical evaluation during the war.
The Q1W carried two low-power engines, allowing for long periods of low-speed flight, and was the first purpose-designed anti-submarine warfareaircraft in the world.