721st Naval Air Group

The 721st Naval Air Group was an Imperial Japanese Navy Air Service aircraft and airbase garrison formation active during the Pacific War. It was established on 1 October 1944 and became associated with the Japanese special-attack program, particularly the Yokosuka MXY7 Ohka piloted rocket aircraft. The unit was also known as the God Thunder Corps, or Jinrai Butai, a name reflecting its intended role in attacks against Allied naval forces. Unlike a single-purpose flying squadron, the 721st Naval Air Group was a composite organization containing operational squadrons, support elements, and airbase personnel. Its structure changed repeatedly as the Japanese naval command reorganized air units during the final phase of the war. At different times it came under the Yokosuka Naval District, the Combined Fleet, the 11th Air Flotilla, and finally the Fifth Air Fleet. These changes reflected the movement of naval aviation resources toward homeland defense and preparation for anticipated Allied operations against the Japanese home islands. The group included an Ohka Squadron from its formation until its dissolution, as well as attack-bomber, fighter, and reconnaissance or bomber-related elements. The attack-bomber component was redesignated the 711th Attack Squadron in November 1944. A Suisei Squadron was also associated with the group, although its aircraft and personnel were transferred to the 722nd Naval Air Group in February 1945. Fighter elements included the 305th, 306th, and 307th Fighter Squadrons. The 708th Attack Squadron served with the group from December 1944, while the 711th Attack Squadron was later disbanded and absorbed into the 708th. The Ohka was designed to be carried close to an Allied target by a parent aircraft, released, and then flown by its pilot in a terminal attack. The 721st therefore depended on both specialized Ohka crews and conventional aircraft units capable of transporting or supporting the weapon. Mitsubishi G4M bombers are closely associated with the Ohka operational concept, while other aircraft types connected with the group included the Yokosuka D4Y Suisei and Japanese naval fighters. The existence of multiple fighter and attack squadrons indicates that the formation also had broader air-defense, training, escort, and base-defense responsibilities. The unit's organization continued to evolve through 1945. The 721st Naval Air Group remained active until 21 August 1945, shortly after Japan's surrender, when it was dissolved. Its history illustrates the Imperial Japanese Navy's late-war shift from conventional fleet aviation toward dispersed land-based air power, homeland defense, and suicide attack formations. It is remembered less as a conventional carrier or fleet air group than as an institutional center for the God Thunder special-attack organization and the operational preparation of Ohka missions.

The 721st Naval Air Group was organized on 1 October 1944 within the Imperial Japanese Navy Air Service. Its initial higher command was the Yokosuka Naval District, and its component structure included an attack-bomber squadron and an Ohka Squadron. The formation was created during a period when Japanese naval planners were expanding land-based aviation and developing special-attack forces for use against Allied fleets. On 15 November 1944, the group was placed under the Combined Fleet. At the same time, its attack-bomber squadron was redesignated the 711th Attack Squadron, and the organization gained or retained additional elements, including the 306th Fighter Squadron and a Suisei Squadron. The group’s defining role remained connected to the Ohka, a piloted rocket-propelled aircraft intended for one-way attacks after release from a carrier aircraft. From 20 December 1944, the 721st came under the 11th Air Flotilla. The 708th Attack Squadron joined the organization during this period. On 1 February 1945, the 305th and 307th Fighter Squadrons were added to the group’s listed structure. These changes show that the formation was not limited to Ohka employment: it also contained conventional fighter and attack units needed for defense, escort, training, logistics, and operation of its airfield complex. On 10 February 1945, command passed to the Fifth Air Fleet. Shortly afterward, on 14 February, the Suisei Squadron’s aircraft and airmen were transferred to the 722nd Naval Air Group. On 15 February, the same transfer process affected the Ohka-associated Suisei element as recorded in the unit’s organizational history. The 711th Attack Squadron was dissolved on 5 May 1945, with its aircraft and personnel transferred to the 708th Attack Squadron. These reorganizations reflected the Japanese effort to consolidate scarce aircraft, pilots, and ground personnel as the war approached Japan’s home territory. The group’s special-attack formations included units identified as the Shinken, Shichisei, Tsukuba, and Shōwa Units. The group was widely associated with the designation God Thunder Corps, or Jinrai Butai. Its operations depended on a combination of specialized attack aircraft and conventional bombers, particularly aircraft capable of carrying the Ohka toward the target area. The Mitsubishi G4M Type 1 attack bomber is commonly linked with this employment concept, while the group’s broader order of battle included naval fighters and the Yokosuka D4Y Suisei. Several fighter squadrons remained associated with the group until 19 August 1945, and the formation itself continued on the Japanese naval order of battle until 21 August 1945. Its commanding officer was Captain Motoharu Okamura, listed as serving from 1 October 1944. The 721st Naval Air Group was dissolved after Japan’s surrender. Its history is consequently tied to the final-war transformation of Japanese naval aviation: from fleet-centered air operations toward dispersed land-based defense and organized special attack.

• 1945

  Transfer to the Fifth Air Fleet

  [1]721st Naval Air Groupen.wikipedia.org

  On 10 February 1945, command responsibility shifted to the Fifth Air Fleet as the group prepared for the final phase of the Pacific War.

• 1945

  Reassignment of Suisei personnel

  [1]721st Naval Air Groupen.wikipedia.org

  Aircraft and airmen connected with the Suisei element were moved to the 722nd Naval Air Group on 15 February 1945.

• 1945

  Disbandment of the 711th Attack Squadron

  [1]721st Naval Air Groupen.wikipedia.org

  The 711th Attack Squadron was dissolved on 5 May 1945, and its aircraft and personnel were transferred to the 708th Attack Squadron.

• 1945

  Dissolution of the air group

  [1]721st Naval Air Groupen.wikipedia.org

  The 721st Naval Air Group was dissolved on 21 August 1945 after Japan’s surrender.

• 1944

  Formation of the air group

  [1]721st Naval Air Groupen.wikipedia.org

  The 721st Naval Air Group was established on 1 October 1944 under the Yokosuka Naval District, with an Ohka Squadron and an attack-bomber component among its initial elements.

• 1944

  Transfer to the Combined Fleet

  [1]721st Naval Air Groupen.wikipedia.org

  On 15 November, the group came under the Combined Fleet. Its attack-bomber squadron was redesignated the 711th Attack Squadron, and further fighter and aircraft elements were associated with the formation.

• 1944

  Placement under the 11th Air Flotilla

  [1]721st Naval Air Groupen.wikipedia.org

  The group was transferred to the 11th Air Flotilla on 20 December 1944, while the 708th Attack Squadron became part of its listed organization.

Imperial Japanese Navy composite air group specializing in late-war land-based aviation and special-attack preparation.

• Piloted rocket-powered special-attack aircraft

  Yokosuka MXY7 Ohka

  The Ohka was the 721st Naval Air Group’s defining weapons system and the aircraft most closely associated with its God Thunder Corps identity. It was intended to be carried by a larger parent aircraft toward an Allied naval target before being released for a high-speed terminal attack. The 721st’s Ohka Squadron and its supporting aviation personnel formed the institutional core of this special-attack mission structure.

• Naval attack bomber

  Mitsubishi G4M Type 1 Attack Bomber

  The Mitsubishi G4M, known by the Allied reporting name Betty, was a principal Japanese naval bomber associated with the airborne delivery of Ohka aircraft. In the context of the 721st, aircraft of this type represented the conventional carrier or transport platform required to bring the specialized weapon near its target. The group also contained attack-bomber formations responsible for broader naval aviation duties.

• Naval dive bomber and reconnaissance aircraft

  Yokosuka D4Y Suisei

  The Suisei Squadron was listed as part of the 721st Naval Air Group for a limited period. Its aircraft and airmen were transferred to the 722nd Naval Air Group on 15 February 1945, making it a temporary component rather than a permanent feature of the formation.

• Fighter aviation

  Naval fighter squadrons

  The 721st’s order of battle included the 305th, 306th, and 307th Fighter Squadrons. These units broadened the group’s responsibilities beyond special attack by providing conventional fighter capability for air defense, escort, training, and protection of the airbase and associated aircraft.

1. 1721st Naval Air Groupen.wikipedia.org