The IJN focused its next major kamikaze effort on Operation Ten-Go, the defense of Okinawa. During this campaign, both the IJN’s 5th Air Fleet and the IJA’s 6th Air Army were under navy control, as an attempt at a more unified tactical approach, with Vice Adm Matome Ugaki in command of the First Mobile Base Air Force. These units were based mainly on Kyushu in southern Japan. The massed Tokko attacks were codenamed as Kikusui (Floating Chrysanthemum) and numbered sequentially. Kikusui became the iconic emblem of the Tokko campaign due to its association with the legendary warrior Kusunoki Masashige. After a heroic but futile defense during the battle of Minatogawa in 1336, Kusunoki committed ritual suicide rather than surrender, uttering the famous slogan: “I wish only that I could be reborn seven times to fight my Emperor’s enemies.” “Seven lives for the Emperor” became the battle-cry of the Tokko force; Kusunoki’s emblem, the Kikusui, became its symbol.
Okinawa was by far the largest and most successful Tokko campaign of the war. It started on March 26, 1945, on a small scale, and followed on April 6 and 7 with the first major wave attack, involving almost 729 Tokko aircraft and escort fighters. This mission was one of the largest Japanese air operations of the entire war. During the Okinawa campaign, the army missions were flown mainly by single-engine fighter and attack aircraft, with the Ki-27 “Nate” (150), Ki-43 “Oscar” (120), Ki-51 “Sonia” (11), Ki-61 “Tony” (60), and Ki-84 “Frank” (60) being the predominant types.
The battleship USS Tennessee moments after being struck by an IJN Aichi D3A Kanbaku (“Val”) dive-bomber of the 2nd Kikusui wave off Okinawa on April 12, 1945 with its bomb penetrating below deck into the warrant officers’ quarters amidships on the starboard side with 22 killed and 107 wounded. (NARA)
The table below summarizes the attacks. Besides the main Kikusui waves, some small-scale raids were also conducted, and there was a separate and distinct set of attacks staged from Taiwan via the island bases of Sakishima Gunto. The IJN exaggerated its victories during the Okinawa offensive, claiming to have sunk 44 ships, including two carriers and eight battleships, while in fact sinking 17 ships including one escort carrier and 11 destroyers, and damaging 279 other vessels. During the Okinawa fighting, nearly a quarter of US warships were hit by a kamikaze.
| Okinawa Campaign Tokko Attacks | ||||
| Mission | Date (1945) | IJN | IJA | Total |
| Kikusui 1 | April 6/7 | 230 | 125 | 355 |
| Kikusui 2 | April 12/13 | 125 | 60 | 185 |
| Kikusui 3 | April 15/16 | 120 | 45 | 165 |
| Kikusui 4 | April 27/28 | 65 | 50 | 115 |
| Kikusui 5 | May 3/4 | 75 | 50 | 125 |
| Kikusui 6 | May 10/11 | 70 | 80 | 150 |
| Kikusui 7 | May 24/25 | 65 | 100 | 165 |
| Kikusui 8 | May 27/28 | 60 | 50 | 110 |
| Kikusui 9 | June 3/7 | 20 | 30 | 50 |
| Kikusui 10 | June 21/22 | 30 | 15 | 45 |
| Additional sorties | April–June | 140 | 45 | 185 |
| Taiwan sorties | April–June | 50 | 200 | 250 |
| Totals | 1,050 | 850 | 1,900 | |
In total, the IJN conducted about 64 percent of all Tokko attacks, and the IJA the remaining 36 percent. During the ten months of the kamikaze attacks, the Tokko missions accounted for 48.1 percent of all damaged US warships, and 21.3 percent of those sunk. These missions expended about 2,500 aircraft and 3,860 aircrew, and scored 474 hits on Allied warships, for an effectiveness rate per sortie of 18.6 percent. US, Australian, and British naval casualties during the kamikaze attacks included more than 7,000 killed.
A US Navy study of the Okinawa campaign concluded that about 10 percent of Tokko aircraft that set off on a sortie had to return to base due to mechanical problems, weather, or failure to locate a target. About half of those reaching the combat area were shot down by CAPs. Only about a third of those that escaped CAPs survived the naval antiaircraft fire and actually hit a ship. Overall, kamikaze aircraft were judged to be seven to ten times more effective per sortie than conventional aircraft attacks. A postwar US Navy assessment concluded that Tokko strikes were more effective than ordinary bomb hits, but substantially less effective than torpedo hits. Further naval studies indicated that the bombs on board the kamikaze were not the main cause of damage, but more often the resulting fires caused in large measure by exploding aircraft fuel.
A group of Tokko pilots hold a brief ceremony before their mission. This event was re-enacted at Chofu airbase in Japan in November 1945 for a film about the kamikaze movement. (NARA)
| Kamikaze Effectiveness vs. Aircraft Carriers | |||
| Weapon | Carriers requiring repairs (%) | Weeks in yard | Weeks out of operation |
| Bomb | 40 | 0.3 | 0.7 |
| Kamikaze | 70 | 1.8 | 4.3 |
| Submarine torpedo | 100 | 10 | 12.4 |
| Aerial torpedo | 100 | 10 | 17.5 |
The US Navy reacted to the kamikaze with new tactics and new technologies that dampened the effectiveness of the Tokko. Destroyers and destroyer escorts were used to establish picket lines around carrier task forces, serving both to extend the radar early-warning network and create a first line of defense against the kamikazes. These picket ships bore the brunt of the kamikaze casualties, because inexperienced Japanese pilots tended to attack the first warship they encountered. During the Okinawa campaign, therefore, destroyers constituted 11 of the 17 lost ships and 109 of the 198 ships and craft that were damaged. The picket ships provided additional time for Navy CAPs to intercept incoming kamikaze flights, and the fighters remained the most lethal antidote to Tokko attacks. The Philippines campaign had also led to a Navy program to increase the number of antiaircraft weapons on ships, and also hastened the deployment of proximity fuzes in antiaircraft shells, which significantly enhanced large-caliber air defense gunfire. The effectiveness of kamikaze attacks therefore decreased between the Philippines campaign and the battle off Okinawa due to both US Navy improvements in gunnery and the declining quality of Japanese aircrews. In the Philippines, about 54 percent of the kamikaze who made it through the CAPs scored a hit or near miss on a ship, but only 32 percent at Okinawa.
One of the final Tokko missions of the war was Operation Arashi (Storm), an attempt in August 1945 to launch Aichi M6A Seiran (Mountain Haze) of the Shinryu Tokubetsu Kogekitai (Divine Dragon Special Attack Unit) from the aircraft-carrying submarine I-400 and I-401 against the US fleet anchorage at Ulithi. The submarines were underway as the war ended, and this Seiran is now on display at the Udvar-Hazy Center of the Smithsonian National Air and Space Museum outside Washington DC. (Author)
| Kamikaze Damage by Type of Ship | |||||
| Attacking aircraft | Hits | Hits per attack (%) | Ships sunk | Sinking per hit (%) | |
| Battleships | 37 | 12 | 32 | 0 | 0 |
| Cruisers | 42 | 15 | 35 | 0 | 0 |
| Fleet carriers | 30 | 10 | 33 | 0 | 0 |
| Light carriers | 10 | 2 | 20 | 0 | 0 |
| Escort carriers | 39 | 15 | 33 | 2 | 13 |
| Destroyers | 303 | 92 | 30 | 12 | 13 |
| Auxiliary/landing ships | 428 | 121 | 28 | 25 | 20 |
| Merchant ships | 55 | 29 | 52 | 6 | 20 |
| Totals | 944 | 296 | 31% average | 45 | 15% average |