Operation Kikusui

On 6 April 1945, the Japanese military commenced Operation Kikusui I (referred to by the Army as the 1st total air assault), with 391 Navy planes and 133 Army planes (of which 215 Navy planes and 82 Army planes were kamikazes) taking part. US Navy anti-air radar picket destroyers deployed in the waters off Okinawa bore the brunt of the attack. At 12:26 pm, the destroyer Haynsworth became the first warship struck. The destroyers Bush and Colhoun were sunk by kamikazes and the destroyers Newcomb and Leutze took heavy damage; the battleship Maryland and 10 other destroyers were targeted by kamikazes as well. The US Navy claimed the loss of 3 destroyers, 1 amphibious warfare ship and 2 munitions transports, along with over 10 other ships heavily damaged.

During Operation Kikusui I, the Surface Special Attack Force, consisting of the battleship Yamato, the light cruiser Yahagi, and 8 destroyers, under the command of Vice-Admiral Seiichi Itō, left for Okinawa to support ground defense operations there, but were repulsed by over 300 carrier aircraft belonging to Admiral Mitscher's Task Force 58 at Bou-no-Misaki, between Kyushu and the Ryukyu Islands, on 7 April; this came to be known in Japan as the Naval Battle of Bou-no-Misaki. The Imperial Japanese Navy lost the battleship Yamato, the light cruiser Yahagi, and 4 destroyers. The Japanese military continued air attacks between 8 and 11 April, and on 11 April the aircraft carrier Enterprise and the battleship Missouri were damaged by kamikaze aircraft, and the aircraft carrier Essex took hull damage below the waterline.

Operation Kikusui II commenced on 12 April, and consisted of 354 Navy planes and 124 Army planes (of which 103 Navy planes and 72 Army planes were kamikazes). Main achievements by the operation include hits on the battleships Tennessee and Idaho; and at least eight other U.S. Navy warships. The human-operated flying bomb Ohka first appeared in Operation Kikusui II; this flying bomb was carried by bombers and was more difficult for US forces to shoot down due to its small size, light weight and high speed. The destroyer Mannert L. Abele became the first and only US Navy ship to be sunk by this type of bomb.

Operation Kikusui III commenced on 16 April, and consisted of 415 Navy planes and 92 Army planes (of which 176 Navy planes and 52 Army planes were kamikazes). Main achievements by the operation include sinking the destroyer Pringle, as well as damaging the aircraft carrier Intrepid and destroyer Laffey, the latter taking six kamikaze and four bomb hits from 22 attackers, earning her the nickname "The Ship That Would Not Die".

Operation Kikusui IV took place from 21 to 29 April, and consisted of 845 Navy planes (of which 126 were kamikazes) and 11 Army planes. Only 3 destroyers were damaged.

Due to Japanese kamikaze attacks in April 1945, US Navy losses in the seas around Okinawa began to climb. With the start of Operation Kikusui V, the US Navy carrier fleet began to receive attention by the kamikazes.

Royal Navy aircraft carrier Formidable set ablaze by kamikaze attacks

On 3 May, 449 planes of the Okinawa Aviation Fleet (including 160 kamikazes) commenced Operation Kikusui V. Main achievements include sinking 2 destroyers, damaging 1 escort aircraft carrier, and damaging the British aircraft carrier Formidable.

United States Navy aircraft carrier Bunker Hill set ablaze by kamikaze attacks

Operation Kikusui VI commenced on 11 May, and consisted of 345 planes (including 86 kamikazes); attacks from 12 to 15 May consisted of 237 planes (including 47 kamikazes). The most significant achievement in these attacks was major damage to Mitscher's flagship, the aircraft carrier Bunker Hill: 2 kamikaze aircraft; the first piloted by Sub Lieutenant Seizō Yasunori, the second by Ensign Kiyoshi Ogawa struck Bunker Hill and triggered large explosions, but did not sink her as a result of improved damage control capabilities on part of US Navy personnel; however, the damage was severe enough that Bunker Hill did not return to the battlefield before the end of the war. Mitscher transferred his flag to the aircraft carrier Enterprise after being evacuated off Bunker Hill. Among the crew, 352 sailors and pilots were killed, 41 disappeared and 264 were wounded.

On 14 May, Mitscher's flagship, Enterprise, was heavily damaged by one kamikaze pilot, Lt. Shunsuke Tomiyasu, resulting in 13 deaths and 68 people wounded. The ship withdrew from the battlefield. As a result, Mitscher transferred his flag to the carrier Randolph.

Operation Kikusui VII took place between 23 and 25 May, and consisted of 387 Navy planes and 174 Army planes (of which 107 Navy planes and 61 Army planes were kamikazes). However, the achievements were quite small compared to the previous operation, with only 1 transport sunk and 1 escort aircraft carrier damaged.

Operation Kikusui VIII took place between 28 and 29 May, and consisted of 217 Navy planes and 71 Army planes (of which 51 Navy planes and 57 Army planes were kamikazes). Due to reduced airstrike capabilities on part of the Japanese military, achievements were small, only sinking 1 destroyer, the USS Drexler and damaging several ships.

Operation Kikusui IX took place between 3 and 7 June, and consisted of 367 Navy planes and 71 Army planes (of which 23 Navy planes and 31 Army planes were kamikazes). Main achievements include damage to the battleship USS Mississippi on 5 June, one escort aircraft carrier and the heavy cruiser USS Louisville on 5 June. In the Okinawa land offensive, the United States had taken the prefectural capital, Naha, and the Japanese were forced into the southernmost tip of Okinawa Island.

Due to the Japanese defeat in the Okinawa land offensive, the Imperial General Headquarters launched one final Kikusui operation between 16 and 22 June, while making preparations for a final showdown on the Japanese home islands. Operation Kikusui X consisted of 271 Navy planes (of which 67 were kamikazes); it achieved only 1 destroyer sunk; and one escort carrier ship damaged.