The Mitsubishi A6M Zero was a lightweight fighter used by the Japanese Air Force and Navy during the Second World War. It was highly manoeuvrable and very successful early in the war but, due to it's lightweight construction and lack of pilot protection, suffered very high casualties later on as the Allies introduced more capable aircraft.
The A6M2-N, codenamed Rufe by the Allies, was a seaplane fighter, a type highly uncommon due to the negative effect on performance caused by the addition of floats. The design was the result of an Imperial Navy requirement drawn up in September 1940 that called for an aircraft capable of providing air support for amphibious assault operations. The aircraft were expected to operate from sheltered lagoons and lakes providing cover until more conventional land based aircraft could operate from permanent airfields.
Nakajima was issued with a contract to modify existing Mitsubishi A6M2 Zero fighters and the first prototype flew on December 8, 1941 becoming operational by July the following year. The new design retained the armament of the Zero but replaced the undercarriage with a large central float, that doubled as a fuel tank, and two wing mounted outrigger floats. The new features bled around 40mph from the top speed of the Zero but didn't affect the manoeuvrability too adversely.