On 12 December 1937, the Imperial Japanese Army Air Force issued a specification to Mitsubishi for a long-range strategic reconnaissance aircraft to replace the Mitsubishi Ki-15. The specification demanded an endurance of six hours and sufficient speed to evade interception by any fighter in existence or development, but otherwise did not constrain the design by a team led by Tomio Kubo（a 1931 graduate from the Aeronautical Section of the Faculty of Engineering at Tokyo Imperial University) whose aesthetics are very significantly infused to the aircraft.