The Kawasaki Ki-100 was a fighter aircraft used by the Imperial Japanese Army in World War II. The Japanese Army designation was "Type 5 Fighter". No Allied code name was assigned to this type, although it may have been misidentified as a Tony due to the similar profile and appearance.
The emergency measure of adapting a Ki-61-II-KAI fighter to carry a Mitsubishi radial engine resulted in one of the best interceptors used by the Army during the entire war. It combined excellent power and maneuverability and, although its high altitude performance against the USAAF Boeing B-29 Superfortress heavy bombers was limited by the lack of an efficient supercharger, it performed better than most other IJAAF fighters.
Operational missions began in March 1945. From the first engagements, the Ki-100 performed well against the B-29 and showed itself to be equally effective against U.S. Navy carrier fighters. A new variant, the Ki-100-Ib, was produced during the last weeks of the war in time to equip five sentai (squadrons) for home defense duties.
Source: Wikipedia, "Kawasaki Ki-100", available under the CC-BY-SA License.
As Described In
Aces of the Pacific: The Kawasaki Ki-100 was a Ki-61 mounting a radial engine. In combat, the Ki-100 demonstrated excellent agility, speed and acceleration. It entered service in Japan starting in March 1945.