The Ki-100 was an emergency measure after the USAAF destroyed the factory producing the Ha-140 (DB605) in early 1945. The ~270 Ki-61-II-KAI, now without engines, were converted to use the Ha-112 radial engine, creating the Ki-100. The Ki-100 had worse performance than the Ki-61-II-KAI, with a top speed similar to the earlier Ki-61-I-KAI (DB601).