The Mitsubishi J2M was a Japanese Interceptor aircraft that was used during World War II. It was designed and developed by Jiro Horikoshi.
The first flight was on 20th March 1942. Production of the J2M2 began in October 1942. Because of technical problems, service entry was delayed to December 1943; at this time, development of the J2M3, a derivative with upgraded armament, had already begun. All in all 476 (including prototypes) aircraft were produced.
The J2M Raiden (=Thunderbolt) recieved the allied codename "Jack" and was first used in 1944. But only at the end of the War the performance of the Raiden was realised. It was a at high altitude operating interceptor, that was first used against the American B-29 bombers, if they attacked at low level flight. It had an aerodynamical design and with its 20-mm machine guns it was able to break through the armor of the B-29. But with the capture of Iwo Jima, the B-29 were escorted by P-51 Mustang, so that the Raiden had to fight the Mustangs and from this point the AA guns and other Interceptors like the Kawasaki Ki-45 had to intercept the Superfortresses. The J2Ms, which defended Japan in 1944-1945 against the bombers of the USAAF, achieved 676 kills.