Giretsu Special Forces with sub machine-gun Type-100.
Captain Okuyama and Giretsu Airborne unit depart on their mission to Okinawa.
The Giretsu (Gallantry) Airborne Unit was formed in the autumn of 1944 to attack B-29 bases in the Marianas. The planned January 1945 Marianas mission was cancelled when forward bases on Iwo Jima were damaged, but in May 1945 the target shifted to US bases recently established around Yontan on Okinawa. Operation Gi was launched on May 24, with Type 97 ("Sally") bombers as transports. Several aircraft returned to base with engine problems, and seven reached Okinawa, with 98 personnel. Some of these aircraft were shot down during the approaches to the runways, and the rest crash-landed before midnight.
On 16 May 1945, the Japanese Sixth Army requested the deployment of the Giretsu Unit to neutralize those airfields. "Operation Gi-gou" deployed on the night of 24May 1945. Japanese air operations included major diversionary bombing attacks throughout the region striking Ie Shima and softening up American defenses defending Yontan and Kadena. Twelve Ki-21II "Sally" medium bombers with 136 commandos departed from Kengun Field, Kumamoto, Japan at dusk for the commando attack. Eight of the bombers, lead by Captain Watanabe, were slated to attack Yontan and four, lead by Captain Okuyama, were to attack nearby Kadena.
The twelve troop laden attacking Giretsu aircraft were to belly land on the runways instead of a conventional parachute assault. This tactic was chosen to gain the element of surprise and most importantly, to deliver their raiders exactly where they needed to be, en mass, to maximize their destructive capability. Descending with wheels up would also decisively shorten their landing and effectively block the runways. The Giretsu knew they were on a mission vital to the Japanese war effort. Objectives included destroying as many aircraft as possible, specifically any B-29's, (of which there were none,) the night fighters of VMF(N) 533, fuel dumps and installations. They were instructed to fight on until relieved. (The Japanese army assured the Giretsu troops there would be additional air and ground attacks the following morning in support of the raiders-those actions never materialized.)
One aircraft actually made it onto Yontan Field during the melee. (Those slated to attack Kadena-never made it to their destination.) During the night five enemy aircraft were intercepted and shot down by VMF(N) 533, and one by VMF(N) 543. Six additional enemy bombers were dispatched by Marine anti- aircraft units protecting Yontan Field. In the aftermath of the attack, the map taken from deceased Captain Watanabe, revealed with large red "X's," the exact positions of where VMF(N) 533, Black Mac's Killers Hellcats were parked and a large red "X" on Black Mac's tent location. They failed to accomplish these objectives. The Giretsu raiders: destroyed 9 aircraft (3 F4U's, 2 PB4Y's [probably mistaken for B-29's], 1 R5C, 3 C47's), damaged 24 others (17 F4U's, 3 F6F's, 2 B-24's, 2 Transports), detonated a 70 thousand gallon fuel storage tank and damaged a number of adjacent installations.
69 Japanese casualties were recovered from the wreckage near Yontan Field, including the 11 aboard the aircraft (tail number 546) that successfully belly-landed. The other 67 Giretsu attackers aboard the remaining 6 Ki-21II bombers did not complete their mission-none of their remains were recovered. The Marines suffered 3 KIA--1st Lt. Maynard Kelley, killed while manning a search light on the deck of the control tower, and two Marines smothered when a crashing "Sally" hit their A-A gun mount. During the fight an additional 18 Marines were wounded. When VMF(N) 533's night fighters, on station when the attack began, ran low on fuel they were diverted to Kadena Field to refuel and standby until they were cleared to return to base. Yontan Field was operational by mid-morning on the 25th. This was the only raid of its kind conducted by the Japanese during the war. The Giretsu raid was a desperate heroic effort mounted by the Japanese Military-but not much more than another night of combat for the Americans involved; operations continued unabated and the outcome was already inevitable.
Bruce Porter recounts the attack in his book, Ace!
"Over a dozen Japanese giretsu commandos survived the suicide landing, and succeeded in destroying a large fuel dump (a total of 70,000 gallons) and planting magnetic grenades to aircraft on the flight line. Three F4U's, two PB4Y's and four transports were destroyed. In addition, 22 other F4U's, 3 F6F's, 2 B-24's and 2 transports were damaged. Only three Americans died in the raid, 18 Marines wounded. Japanese losses were 69 pilots, aircrews and raiders."
Joseph Alexander, The Final Campaign Marines Victory on Okinawa
"Another bizarre Japanese suicide mission proved more effective. On the night of 24-25 May, a half-dozen transport planes loaded with Giretsu, Japanese commandos, approached the U.S. airbase at Yontan. Alert antiaircraft gunners flamed five. The surviving plane made a wheels-up belly landing on the air strip, discharging troops as she slid in sparks and flames along the surface. The commandos blew up eight U.S. planes, damaged twice as many more, set fire to 70,000 gallons of aviation gasoline, and generally created havoc throughout the night. Jittery aviation and security troops fired at shadows, injuring their own men more than the Japanese. It took 12 hours to hunt down and kill the last raider."
The IJN also planned Operation Ken-gou against the Marianas bases using 300 troops of the Special Naval Landing Force carried by 30 Betty bombers. US forces, however, discovered the plan from radio intercepts and the transport force was destroyed at Misawa airbase by a US carrier air strike on July 14, 1945. At least two other large raids were ready in August 1945, including an IJA attack using gliders, but the war ended before they took place.