The Mitsubishi F1M was developed to meet the Imperial Japanese Navy's 10-Shi requirement for a new observation seaplane. The prototype first flew in June 1936, with some sources specifying the date as June 22, 1936. The initial version, the F1M1, was powered by a Nakajima Hikari 1 air-cooled 9-cylinder radial engine producing approximately 820 hp. However, the F1M1 suffered from poor stability and handling, particularly during water operations, leading to a substantial redesign.
This redesign resulted in the F1M2 production model, which featured a shortened wingspan, modified tail and floats, and a more powerful Mitsubishi MK2C "Zuisei 13" 14-cylinder radial engine. The Zuisei 13 provided 875 hp at take-off and 800 hp at 3,500 meters. Mass production occurred between approximately 1939 or 1940 and 1944. Production totals vary by source; while some records indicate 944 aircraft were built, other detailed accounts cite 1,118 units. These were manufactured at Mitsubishi's Nagoya plant, the 21st Naval Air Arsenal, and the Sasebo Naval Arsenal.
Designed primarily for gunnery spotting and reconnaissance, the F1M2 proved remarkably versatile. It served as a convoy escort, maritime patrol aircraft, and light bomber, capable of carrying two 60 kg bombs or a single 250 kg bomb for special attacks. Its agility allowed it to operate as an area-defense fighter, engaging Allied aircraft in theaters such as the Solomon Islands, New Guinea, and the Aleutians. A notable combat success occurred on April 9, 1942, when F1Ms sank the American PT-34 motor torpedo boat near the Philippines.
Technically, the F1M2 achieved a maximum speed of 370 km/h at 3,440 meters and could climb to 5,000 meters in 9 minutes and 36 seconds. It was carried aboard a wide array of IJN capital ships, including the battleships Yamato, Musashi, and Nagato, as well as various cruisers and seaplane tenders. Beyond the Imperial Japanese Navy, the aircraft was operated by the Royal Thai Navy and was later used by Indonesian forces during the Indonesian National Revolution after the Japanese surrender.