The Japanese military favored aircraft with airframe weight reduced to the minimum, which provided outstanding maneuverability and a very long range at the expense of aircraft durability. This approach proved efficient for maneuvering engagements at low to mid altitude. It culminated in the development of the А6М Zero series of fighters.
By the end of WWII, Japanese designers faced the necessity to improve aircraft speed and altitude performance, as well as survivability. They had partial success with the unique Kyushu J7W series; however, the new fighters were never tried in action due to the end of the war.