The Kanoya Air Group was formed on 1 April 1936 and was the oldest medium bomber air group in IJNAS, along with the Kisarazu Air Group. It initially operated from Kanoya on Kyushu and was equipped with Type 96Mitsubishi G3M medium bombers. They first saw combat during the Second Sino-Japanese War in August 1937. In July 1941, the air group temporarily moved to an airfield near Hankou in Central China to participate in Operation 102, which involved concentrated attacks against targets in Chongqing and Chengdu in West China. Following the unit's return from Hankou to Kanoya in September 1941, they became the second IJNAS unit to be equipped with the new Type 1Mitsubishi G4M medium bombers. In November, they moved to Taiwan, however soon afterwards the unit's main body was transferred to Saigon in French Indochina, leaving a detachment at Taichung. The detachment that stayed on Taiwan participated in the attack on the Philippines. At the start of Pacific War, Kanoya Air Group was considered the most highly trained medium bomber unit in torpedo attacks. Therefore, its main body at Saigon was selected as the main torpedo attack unit for the attack on the newly arrived British naval Force Z, centered around the battleship and battlecruiser. The attack formation of 26 G4M bombers was led the unit's HikōtaichōLieutenant Commander Shichiso Miyauchi, who flew as an observer in the lead aircraft, piloted by BuntaichōLieutenant Miyoshi Nabeta. By the time they arrived to the area off the south-east coast of Malay Peninsula, where the ship were heading back to Singapore, the Royal Navy ships had been already attacked by the older G3M bombers from Mihoro Air Group and Genzan Air Group. A high level attack by Mihoro's bombers hit Repulse with a single 250 kg bomb that caused a minor damage, while Genzan's bombers hit Prince of Walse with two torpedoes that hindered her steering ability. Kanoya's torpedo attack then hit Repulse with four torpedoes and finished off Prince of Walse with additional four torpedoes. The attack sank both battleships at the cost of two Kanoya's bombers. In January 1942, the detachment first moved to the newly captured airfield at Davao and then to Kendari and participated in the invasion of Dutch East Indies, while the main body supported the Japanese invasion of Malaya and Singapore. On 19 February, the detachment participated in the Bombing of Darwin, where they hit the harbor one and a half hour after the carrier strike. In March, the main body and the detachment both returned to Japan where they reunited. In September 1942, the unit moved to Kavieng on New Ireland to participate in Guadalcanal campaign and New Guinea campaign. On 1 October the unit was renamed to 751st Air Group according to the re-designation of IJNAS units. In April 1942, the unit participated in Operation I-Go. By mid-1943, the high rate of attrition forced the unit to reduce the number of aircrew per bomber from seven to five, which typically meant there was no co-pilot. After US carrier force raidedTruk Lagoon in February 1944, all air units were withdrawn from Rabaul area, including 751st.
