In 1939, the Naval Aviation Headquarters conceived a plan of trial manufacturing a floatplane fighter, a new type beyond all precedents in the world. On the assumption of landing and invading the Southern regions, the Japanese Navy intended in those days to station float planes in waterways and bays near the landing places until the completion of land air bases for the purpose of defending those under construction and occupied territories. Since the floatplanes might have to fight with enemy fighters in the air, they were required to be pure fighters comparing favorably with enemy fighters in performance. The Navy firmly believed that sufficiently armed floatplanes would be able to fight on equal terms with fighters considering that Type 95 Scout Seaplanes shot down Chinese fighters as successfully as did land based fighters at the early stage of the sino-Japanese incident. In 1940, the Naval Aviation Headquarters decided to trial manufacture floatplane fighters and ordered Kawanishi Aircraft, which was well experienced in manufacturing floatplanes, to trial manufacture them under the name of 15- Shi Floatplane fighter (later called Floatplane Fighter "Kyofu").