In 1937, in light of combat reports from China, the Imperial Japanese Navy established specifications for a new carrier fighter aircraft. The aircraft had to achieve a maximum speed of 500 km/h at 4000 meters; a climb to 3000 meters in 3.5 minutes; an endurance a 1.5 to 2 hours at normal power and fully loaded and with additional fuel tank; or 6 to 8 hours at economical cruising speed; armament requirement consisted of two 20mm cannons and two 7.7 mm machine guns, and two 30 kg or 60 kg bombs; a complete radio set; a wing span of less than 12 meters; and maneuverability at least comparable to the A5M type 96 aircraft