The Mitsubishi Ki-1 was also designated Mitsubishi Army Type 93-I Heavy Bomber under the long aircraft nomenclature system used by the Japanese military.
The design was upgraded to the Mitsubishi Ki-1-II (Mitsubishi Army Type 93-II Heavy Bomber) with a strengthened airframe and slightly more powerful Mitsubishi Ha2-III V-12 engines, which increased maximum speed to .