By early 1945 an urgent need for an easy to manufacture and maintain light bomber was needed. In March 1945 the Japanese Army Air Force ordered Kawasaki to begin design work for an aircraft that had the following requirements:
- Range of 373 miles / 600 km
- Bomb load of 1,764 lb / 800 kg
- Armament of two 20 mm Ho-5 cannons
- Powered by an Army Type 4 engine
- Be manufactured at dispersed underground factories
By June 1945 Takeo Doi and Jun Kitano completed the basic design. Many of the features were based on the Ki-100.
The Ki-119 could also be used as a dive bomber with two 551 lb / 250 kg bombs, or as a fighter escort with two 20 mm Ho-05 cannons added in the wings.
Air raids in June 1945 destroyed the design drawings and had to be recreated. It was hoped to have the first prototype ready to fly in November 1945 but with the surrender of Japan all work was stopped.