Question: Which Japanese fighter was the predecessor of the "Reisen?"
Context: Toshio Ōta (太田 敏夫 , Ōta Toshio , 20 March 1919 – 21 October 1942) was a World War II Japanese fighter ace.  In early 1942, at the age of 22, he flew a Mitsubishi A6M Zero with the Lae based Tainan Air Group.  There the young petty officer, 1st class became one of the so-called "Clean-up Trio" of Japanese aces, along with his squadron mates Saburo Sakai and Hiroyoshi Nishizawa. Dr. Jiro Horikoshi (堀越 二郎 , Horikoshi Jirō , 22 June 1903 – 11 January 1982) was the chief engineer of many Japanese fighter designs of World War II, including the Mitsubishi A6M Zero fighter. The Akutan Zero, also known as Koga's Zero and the Aleutian Zero, was a type 0 model 21 Mitsubishi A6M Zero Japanese fighter aircraft that crash-landed on Akutan Island, Alaska Territory, during World War II.  It was found intact by the Americans in July 1942 and became the first flyable Zero acquired by the United States during the war.  It was repaired and flown by American test pilots.  As a result of information gained from these tests, American tacticians were able to devise ways to defeat the Zero, which was the Imperial Japanese Navy's primary fighter plane throughout the war. The Kawasaki Ki-61 "Hien" (飛燕, "flying swallow") is a Japanese World War II fighter aircraft used by the Imperial Japanese Army Air Service.  The Japanese Army designation was "Army Type 3 Fighter" (三式戦闘機).  Allied pilots initially believed Ki-61s were Messerschmitt Bf 109s and later an Italian aircraft, which led to the Allied reporting name of "Tony", assigned by the United States War Department.  It was the only mass-produced Japanese fighter of the war to use a liquid-cooled inline V engine.  Over 3,000 Ki-61s were produced.  Initial prototypes saw action over Yokohama during the Doolittle Raid on 18 April 1942, and continued to fly combat missions throughout the war. The Mitsubishi A6M "Zero" is a long-range fighter aircraft, manufactured by Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries, and operated by the Imperial Japanese Navy from 1940 to 1945.  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" (zero fighter), "0" being the last digit of the imperial year 2600 (1940) when it entered service with the Imperial Navy.  The official Allied reporting name was "Zeke", although the use of the name "Zero" was later adopted by the Allies as well. The Mitsubishi A5M, formal Japanese Navy designation Mitsubishi Navy Type 96 Carrier-based Fighter (九六式艦上戦闘機), experimental Navy designation Mitsubishi Navy Experimental 9-Shi Carrier Fighter, company designation Mitsubishi Ka-14, was a Japanese carrier-based fighter aircraft.  It was the world's first monoplane shipboard fighter to enter service and the direct predecessor of the famous Mitsubishi A6M "Zero".  The Allied reporting name was Claude. The Mitsubishi 1MF9 or Mitsubishi Experimental Taka-type Carrier Fighter was a prototype Japanese fighter aircraft of the 1920s.  It was a single-engined, single-seat biplane intended to operate from the Imperial Japanese Navy's aircraft carriers, but only two were built, with the type being rejected by the Navy. The Nakajima Ki-84 "Hayate" (キ84 疾風"Gale" ) was a single-seat fighter flown by the Imperial Japanese Army Air Service in the last three years of World War II.  The Allied reporting name was "Frank"; the Japanese Army designation was Army Type 4 Fighter (四式戦闘機 , yon-shiki-sentō-ki ) .  The Ki-84 is generally considered the best Japanese fighter to see large-scale operation during the conflict.  The aircraft boasted high speeds and excellent maneuverability with an armament (up to two 30 mm and two 20 mm cannon) that gave it formidable firepower.  The Ki-84's performance matched that of any single-engine Allied fighter it faced, while its operational ceiling enabled it to intercept high-flying B-29 Superfortress bombers.  Pilots and crews in the field learned to take care with the plane's high-maintenance Nakajima Homare engine and landing gear prone to buckling.  The difficulties of Japan's situation late in the war took a toll on the aircraft's overall field performance as manufacturing defects multiplied, quality fuel proved difficult to procure, and experienced pilots grew scarce.  Even then, the pilot of a well-maintained Ki-84 took to the skies in knowing possession of Japan's fastest fighter.  A total of 3,514 aircraft were built. Isamu Mochizuki (Japanese: 望月 勇 ; 1906 – February 6, 1944) was an officer and ace fighter pilot in the Imperial Japanese Navy (IJN) during the Second Sino-Japanese War and the Pacific theater of World War II.  In aerial combat over China and the Pacific, he was officially credited with destroying seven enemy aircraft.  During his flying career, Mochizuki invented the half loop and roll technique used in dogfighting by Japanese fighter pilots.  He was stranded on Roi-Namur Island with no aircraft to fly after the American invasion on 6 February 1944.  Mochizuki disappeared and was presumed killed in action in ground combat with the enemy. The Nakajima Army Type 91 Fighter was a Japanese fighter of the 1930s.  It was a single-engine, single-seat parasol monoplane with a fixed, tailwheel undercarriage.
Answer: The Mitsubishi A5M