On May 1, General Buckner substituted the 1st Marine Division for the battered Army 27th. He reassigned the latter to security duty in the occupied northern portion of the island for the balance of the campaign. The 96th Division was replaced by the 77th, available after completion of the takeover, in a bloody battle, of the smaller Ie-Shima Island to the north. Buckner also planned to substitute the 96th for the 7th, after the former had been rested and brought up to full strength.
The Total Japanese Losses in Their Fruitless Counterattack Reached 6,227 Dead.
General Cho had not given up his conviction that a forceful counterattack would blunt the American advance. He pointed out that now the 1st and 6th Marine Divisions would be thrown into the fight by the Americans. Once more, Cho convinced General Ushijima to authorize another even more complicated strike against the American positions. In addition to the direct frontal assault on American lines, Japanese troops would also utilize small boats launched from Naha to land troops behind them at night. At the same time, a powerful kamikaze attack against American naval units would be undertaken to turn attention away from the land offensive. Ushijima acquiesced to the plan.
On May 3, the second counterattack began. The Japanese 24th Division, charged with breaking through the American positions with a direct frontal assault, took a fearful beating. The Japanese failed to make any meaningful penetration of American positions, and their efforts to land infiltrators behind American lines by boat met the same fate. By May 5, it became clear to General Ushijima that the offensive had failed. The total Japanese losses in this fruitless counterattack reached 6,227 dead.
Seeing an opportunity to exploit these losses, Buckner’s subordinates now urged him to approve a landing by either Army or Marine units on beaches behind the Japanese defensive lines at Minatoga, a port on the island’s south end. Pressure also came from Admiral Turner who wanted Okinawa quickly won to reduce the attrition being suffered by his naval units off Hagushi Bay. Marine Maj. Gen. Lemuel Shepard urged the use of the 2nd Marine Division. The Marine general pointed out that the 2nd could undertake a month’s operations with the supplies, both food and ammunition, that it had on hand.
Buckner continued to refuse the recommendations for the establishment of a second front, citing a continuing shortage of ammunition, the difficult reef conditions at possible landing sites in the Minatoga area, and a concern for the strength of the Japanese forces still protecting the beaches there. He continued to press forward against the still strongly defended Shuri Line.
The III Amphibious Corps, consisting of the 1st and 6th Marine Divisions, occupied the right, or western, flank of the American position, while the Army’s XXIV Corps, consisting of the 77th and 96th Infantry Divisions, held the left, or eastern, flank. Buckner’s plan called for the two corps to swing in from both coasts, flanking the Japanese positions.
The battle broke down into a series of individual attacks by the Americans similar to the Kakazu action in which the Japanese had to be destroyed in each of their heavily fortified bunkers and caves by infantrymen attacking directly, aided by the use of flamethrowers and satchel charges. Neither heavy artillery from naval forces nor bombing could accomplish the task.
The 6th Marine Division sought to turn Ushijima’s flank on the west by fording the Asa River and crossing the Kokuba Hills into the Kokuba Valley. The 1st Marine Division, operating east of the 6th, planned a direct assault on Shuri itself. They faced Dakeshi and Wana Ridges as their initial targets.
The Army’s 77th Infantry Division opened up its drive to the south with an attack on the Japanese lines in the center of the island. Facing them were two fortified positions, one called Chocolate Drop, covered by fire from the other, Flattop Hill.
Finally, the 96th Infantry Division, occupying the extreme eastern wing of Buckner’s attacks, planned to break the Japanese flank that ran from Yonabaru. There they would be forced to take Conical Hill, protected by the Japanese 89th and 22nd Infantry Regiments. The Dick-Oboe Hill complex, also a critical target, lay ahead on the boundary between the two American Army divisions.
When the 6th Marine Division moved south to encircle the Shuri bastion, it encountered a well-defended position, Sugar Loaf Hill, protected on each side by Horseshoe and Half Moon Hills. On May 17, in a desperate struggle, the Marines took the three positions at the cost of 2,662 casualties.
The 1st Marine Division encountered the same type of resistance in its attacks on Dakeshi Ridge, Wana Ridge, and Wana Draw. There they had the support of tanks, protected by infantry this time, and heavy bombardment from naval units offshore. The Navy fired a half-million rounds into the disputed area even though the ships themselves were under constant threat from kamikaze attacks. On May 21, the 1st finally achieved its objective, but like the 6th, at heavy cost.
The 77th Division, charged with the capture of Chocolate Drop and Flattop, made slow progress. It took over a week to secure Flattop and several days after that to wipe out all resistance in isolated caves. The Chocolate Drop bastion fell to the 77th on May 21.
It was the 96th Division, operating along Buckner Bay, that finally broke the Shuri Line. The capture of Conical Hill opened up the city of Yonabaru to the Americans and allowed them to spill out into southern Okinawa. Attempts to completely encircle the Japanese positions around Shuri itself failed, though, due to the commencement of heavy rains that seriously impeded any progress along the front.
The Japanese High Command realized that continued resistance at Shuri would result in ultimate destruction despite their fanatical resistance. American staff officers believed that their opponents would remain at Shuri and fight to the bitter end. The Japanese had actually begun plans for the evacuation from their now untenable position before they found themselves surrounded. The continuous hard rains and overcast hid to some degree the Japanese withdrawal.
Japanese Directives Called for the Execution of all 100,000 Allied POWs Once Japan was Invaded. A Protracted Invasion Effort Would Certainly Result in the Deaths of Most of the Prisoners.
On May 22, the Japanese began their retreat. First they began to move their supplies and wounded. The new command post for the 32nd Army would be established on Hill 89 at Mabuni on the island’s southernmost coast. By May 28, the bulk of the Japanese defenders had evacuated the Shuri area, leaving only rearguard elements to slow the advance of the American forces. Later, the American commanders admitted that Ushijima’s retreat, despite substantial losses, had proven to be an impressive military operation. Unfortunately, those civilians that chose to accompany the Japanese troops paid a heavy price in terms of both injury and death.
By June 3-4, the Japanese established their final defensive position toward the southern tip of the island on the Yaeju-Dake Escarpment. A separate smaller segment, mostly naval troops, held positions on the Oroku Peninsula to the northwest of the newly established Yaeju-Dake defenses. The Navy men held out for 10 days before being overwhelmed by the 1st Marine Division. The Japanese commander, Admiral Minoru Ota, committed suicide along with his immediate staff.
At Yaeju-Dake, improved weather permitted more extensive employment of flamethrower tanks and satchel charges against the entrenched Japanese. On June 18, General Buckner, standing at a forward observation post, was wounded when a Japanese shell blew up a coral formation near him and a piece of the coral was driven into his chest. He died 10 minutes later. Marine General Geiger assumed overall command.
Finally, on June 21, formal Japanese resistance ended. For the first time in the Pacific War, substantial numbers of soldiers surrendered rather than continuing a hopeless fight. Not so Generals Ushijima and Cho. Together they committed hara-kiri, ritual Japanese suicide, on the heights of Mabuni overlooking the ocean, at 4 am on June 22. The fighting for the island ended after 82 days.
Total American casualties during the Okinawa campaign numbered 49,151. Deaths numbered 12,427, with 4,907 Navy, 4,582 Army, and 2,938 Marine personnel paying the ultimate price. Japanese deaths alone reached 110,000. The 32nd Army was virtually destroyed. In addition, some 160,000 Okinawan civilians perished in the conflict.
What did the Okinawa victory gain for the Allies? First, it provided them with a base only 380 miles from the Japanese Home Islands. From this close proximity to the heart of the Japanese Empire, multiple attacks by land, sea, and air could be launched in the anticipated invasion of Japan proper. The war could be brought home forcefully to the enemy in a matter of a few short months.
For the Japanese, defeat on Okinawa had been costly. They were now at the mercy of an increasingly powerful enemy at their doorstep. They had lost over 70,000 of their veteran front-line troops, plus the balance of their Navy and at least 20 percent of their remaining military aircraft.