The A6M was designated as the Mitsubishi Navy Type 0 carrier fighter (零式艦上戦闘機, rei-shiki-kanjō-sentōki), or the Mitsubishi A6M Rei-sen. The A6M was usually referred to by its pilots as the Reisen (零戦, zero fighter), “0” being the last digit of the imperial year 2600 (1940) when it entered service with the Imperial Navy.
