The Seiran crews stood at attention as Ariizumi stopped in front of each man and presented him with his sword. No written order had been issued declaring the mission a suicide attack, but no such order was necessary. The men knew what the sword implied. It meant fight to the death.43
Heiji Kondo watched from the I-401’s bridge as Asamura was handed his sword. The little Seiran pilot quivered with emotion as he grasped its hilt. But it wasn’t Asamura’s shaking that moved Kondo, it was the expression on his face. Conflict was written there, the conflict between seriousness of purpose and the will to live. Although Asamura was overcome with emotion, he did not hesitate. He’d vowed in his heart to die for the mission, and though he couldn’t speak for the other pilots, he knew what he must do.44
Takahashi felt the blood drain from his face as Ariizumi handed him his sword. Is this finally the end? he wondered.
After the ceremony was over, public relations officers flocked around the Seiran crews, handing them thick squares of expensive paper on which to write their last words. The results would appear in a future issue of Japanese newspapers and be preserved at Etajima for posterity.
Takahashi thought for a moment before dipping his brush into a pool of black ink. When his words had dried, he thought they’d captured his feelings, perfectly.
“I do not regret giving my life for my country,” he’d penned. “But what will become of my mother?”45
* There is some confusion around when and where Ariizumi briefed his men about the Ulithi mission. According to some accounts, he did so before he left for Tokyo, when the I-13 and I-14 were still present with their full complement of Seiran. If this is the case, it seems unlikely he would have pleaded to continue the Panama Canal mission when he met with the NGS. Since Ariizumi clearly fought the decision to cancel the Panama Canal mission, he probably waited to brief his men until he returned from Tokyo. If he briefed them upon his return to Nanao, part of his fleet might well have been missing. However, if he waited until he reached Maizuru, the I-13 and I-14 had already departed for Ominato. The dates provided by the historical record are contradictory, confusing, or incomplete.
† Both Nambu and Sato recalled that the farewell dinner in Maizuru was held on July 19. Takahashi, however, said it was July 18.
‡ Nambu says the ceremony took place on July 20, as does Sato. However, if the I-401 arrived in Maizuru on July 13 as Sato suggests, it means the sub remained in Maizuru for eight days, not the seven days he claims.
PART V
RACE AGAINST TIME
CHAPTER 29
DEPARTURE
THE I-400 LEFT MAIZURU NAVAL BASE ON JULY 21, 1945.1 LED BY a minesweeper, the sub motored slowly on the surface, while a reserve Seiran aircrew ran along the shoreline shouting encouragement.2
Takahashi had no more stomach for tearful goodbyes. “Get out of here, you idiots,” he shouted at his comrades. “I don’t want to see your face.”3
Kusaka’s sub was heading for Ominato,4 a naval port near the northern tip of Honshu. Ominato was the final departure point for the Sen-toku force. Situated on Mutsu Bay, a day’s journey, the port provided access to the Pacific Ocean through the well-guarded Tsugaru Strait. It was virtually the only exit from the Sea of Japan that the Sixth Fleet could still use.
Before Nambu followed in the I-401, he raised a banner on the bridge.5 Meant to inspire his crew it proclaimed in large, bold characters, “Japan, land of the gods.”6 But it seemed like the gods had abandoned Japan. An increasing number of bombing raids had taken place since the first attack in November 1944, and the recent addition of carrier-based attacks only increased the pressure. Every night U.S. Armed Forces Radio filled the airwaves with a Japanese-language broadcast listing the cities to be destroyed by morning. As one submariner noted, in terms of propaganda “it sure beat ‘Tokyo Rose.’ ”7 For those who didn’t have radios, B-29s dropped leaflets. “Read this carefully as it may save your life,” one pamphlet explained. “In the next few days, four or more of the cities named on the reverse side will be destroyed by American bombs.”8 Japanese records estimated that by the end of July 1945, at least half a million civilians had been killed in nationwide air strikes, with another million injured. B-29s were hammering the civilian population so often, they were being driven to the point of insanity.9
If Japan’s civilians were terrified, her military remained unmoved. To get the point across, Allied forces launched air strikes against naval bases at Yokosuka, Kure, and Sasebo. By the end of July, little remained of the Imperial Japanese Navy except smoking hulks.
The raids had an impact on the I-400 subs still under construction. The I-402, which had been converted into a gigantic fuel carrier, was unharmed, but the I-404, which had been moored off Kure awaiting completion,10 was sunk by U.S. carrier planes.11 And though work had commenced on the I-403 and I-405,* 12 it had since been abandoned along with the underwater aircraft carriers I-406 through I-417.13
The I-13 and I-14 were first to arrive at Ominato on July 4.14 The subs were there to load two Saiun aircraft each, which were partially disassembled, crated, and waiting dockside.15 The Nakajima C6N Saiun was a single-engine, carrier-borne reconnaissance aircraft, but by the time Ariizumi needed the planes, there were no Japanese carriers left for them to fly off of.
Built by Nakajima, the Saiun carried a pilot, a navigator (who doubled as an observer), and a radio operator (who doubled as a gunner when the plane came under attack). The Saiun could outrun a Grumman F6F Hellcat, and Nakajima was so confident in the plane’s speed, it had built a night fighter version.16 Her Allied code name was “Myrt,” but Saiun, which means “Painted Cloud,” was far more poetic.
The I-13 and I-14 had conducted live-fire exercises while in Mutsu Bay. Using their largest deck gun, they had fired long distance to perfect their aim.17 And since the war had reduced shipping traffic to almost nothing, there was little chance of hitting anything they didn’t want to.
The I-14 was scheduled to leave Ominato first, followed by the I-13,18 but the bearings19 in the I-14’s prop shaft20 overheated, requiring repair. As a result, the I-13 left Ominato on July 11.† 21 The crew’s friends and family were invited for the sendoff. Since it was the last time they were likely to see one another, the parting was emotional. The crew lined up on deck wearing white headbands with the characters for “Certain Victory” spelled out.22 As the surrounding mountains bore silent witness to the painful parting, the I-13 got slowly under way.
U.S. battleships had already begun shelling northern Honshu and Hokkaido by then.23 It was the first time U.S. naval gunfire had been directed against the Japanese mainland.24 The Kaminishi ironworks, south of Ominato, were reduced to scrap metal,25 and railyards and harbors were targeted as well. Ominato was also on the list.
During the time it took to repair the I-14, Allied air raids repeatedly forced her to the harbor floor. It must have been frustrating to constantly crash-dive as carrier planes attacked, yet that didn’t prevent the I-14 from riding out the raids on the bay’s bottom. Captain Shimizu guessed they’d be spending most of the voyage to Truk submerged; a little more underwater time wouldn’t hurt.26
Despite being attacked day after day, the I-14 managed to depart Ominato on July 17.27 It’s remarkable that any of the I-400 subs managed to escape during this period, especially since Maizuru and Ominato were on the receiving end of several significant attacks. Large in size and slow to submerge, the subs were sitting ducks when anchored in a harbor. Nambu’s former sub, the I-361, had been sunk earlier in the month. Only three of her crew had survived.28 Every submarine Nambu had served on since the beginning of the war had now been destroyed. The I-401 was the last one left.
NAMBU REACHED OMINATO on July 22.29 It was early evening, and there was a drizzling rain as the I-401 sailed into the harbor.30 Kusaka’s sub had arrived a few hours earlier. Since the I-401 had been replenished at Maizuru, her stay at Ominato was brief. Nambu gave half his crew permission to go ashore, while the other h
alf remained to load perishables.31 It would be their last chance to enjoy such delicacies as mackerel and the other fresh foods that were available in Ominato.
Takahashi was one of the lucky ones granted shore leave. He knew it would be the last time he’d set foot on land, so he savored the few hours he had. First he enjoyed a hot bath. Then he sat down to write his will. There were many things he wanted to say to his mother. Unfortunately, everything he wrote sounded sentimental or whiny, so he kept the letter simple. When he was finished, he gave it to two junior officers to deliver, along with the short sword Ariizumi had presented him and the 100 yen in bonus pay he had left. Stripped of his belongings, Takahashi felt relieved.32
While Takahashi spent the evening arranging his personal affairs, Ariizumi dined with a friend. Dinner was a sedate affair compared to Ariizumi’s last evening at Maizuru. He enjoyed two extra helpings of his favorite dish, accompanied by his usual intake of liquor.33 This seemed a more fitting way to spend his last night ashore than singing drinking songs and giving emotional toasts.
Kondo, one of the Seiran mechanics, enjoyed a cup of sake that night. After the day he’d had, he deserved it. Kondo had been detailed to paint one of the I-401’s Seiran. For some reason, the planes hadn’t been disguised in Maizuru, and Kondo was assigned to rectify this. He didn’t have strong feelings about the task; he was just carrying out orders. Regardless, there was no denying how strange a Seiran looked disguised as an American plane.34
Kondo had been painting the fuselage earlier in the day when a Japanese patrol craft appeared overhead. The plane took Kondo by surprise. There were so many American fighters around that the Japanese aircraft could easily have mistaken the newly disguised Seiran for the enemy. Kondo rounded his back in an awkward attempt to hide the American markings. As the patrol craft circled, he stood frozen, his face only inches from the wet paint. Fumes filled his nose and his eyes began to water as Kondo maintained the uncomfortable position. The situation would have been funny if it hadn’t been so dangerous.
The air patrol eventually lost interest and flew away.35 If Kondo had been attacked, there was nothing he could have done but run. The irony alone would have been enough to kill him. As it was, he managed a sigh of relief.
The I-400 left Ominato the next day at 2:00 P.M. Two hours later the I-401 followed.‡ The rain had finally stopped, making for a beautiful afternoon.36 The sun was beginning to set, and the Shimokita Mountains loomed green and lovely in the background.37 Since Nambu expected this to be his last view of Japan, he seared it into his memory.38 He had no way of knowing the I-401’s mission would be the Sixth Fleet’s final offensive of the war.
There was constant fear of enemy subs penetrating the Tsugaru Strait, and of course Halsey’s Third Fleet was not far away. Fortunately, the only things Nambu passed as he sailed through the strait were fishing boats. Then at two in the morning, a water spout erupted behind the sub’s stern.39 It was followed seconds later by a loud report.40
A bridge lookout pointed at a flash from the Hokkaido coastline. Moments later another shell smacked into the sea, this time off their port side. The I-401 was under attack.41
“Submerge immediately!” Nambu cried.42
A Japanese shore battery had spotted the sub’s silhouette and, thinking her the enemy, opened fire. Nambu dove his sub before the shore battery had a chance to improve its aim, but it had been a close call.
The I-401’s captain was so disturbed by the incident, he kept repeating “Dangerous, dangerous” under his breath.43 Ariizumi was incensed enough to fire off an angry radio message scolding the army for its trigger-happy response.
It’s no surprise that friendly fire almost sunk Nambu’s sub, especially since it was operating in secret. At least Japan’s coastal forces were paying attention. This might have been cold comfort, but if Ariizumi’s mission failed, a strong defense would be necessary.
It was up to the I-401 to see that it wasn’t needed.
* There is some dispute as to how much work was done on the I-403. Some Western historians claim the sub was canceled before its keel was laid. However, since both Nambu and Sato, members of the Sen-toku squadron and the 631st, respectively, state construction had begun on the I-403, it seems reasonable to assume that it had.
† Dates for when the I-13 left Ominato for Truk vary (depending on source) from July 2 to July 15. In Sunk! (p. 139), Mochitsura Hashimoto says both subs left Ominato on July 15, while Orita (p. 300) says it was July 2. Both accounts seem wrong because we know the two subs left on separate days. Additionally, in Undersea Victory (p. 473), W. J. Holmes says the I-13 left Ominato on July 5, which also seems too early, since most accounts have the subs arriving at (not departing) Ominato around this time. Though it’s impossible to know for sure, it seems the I-13’s departure was closer to July 11.
‡ Both Sato and Takahashi say the I-401 left two hours later. However, Nambu remembers it as only one hour later, while Asamura says there was a six-hour interval.
CHAPTER 30
UNDER WAY
THE DAY AFTER THE I-401 LEFT FOR ULITHI, AICHI’S NAGOYA facility was bombed again, causing extensive damage. It was the second such attack in July, so when Aichi rolled its twenty-eighth Seiran out the hangar door, it was its last.
Aichi wasn’t alone in this problem. The entire Japanese war machine had ground to a halt. The U.S. sub embargo was squeezing Japan for all she was worth. Meanwhile, Admiral Halsey’s armada was closing in.
Ariizumi knew his special attack force was surrounded, but he had two tricks he was counting on to escape undetected. The first was the snorkels he’d installed in May. The longer they helped him hide beneath the surface, the better they could avoid radar. The second trick was the two special anechoic coatings on the outside of each sub designed to improve their stealth factor. The U.S. Navy didn’t need snorkels or stealth coatings, but Ariizumi believed them to be one of the few advantages he possessed besides the courage of his crew.
By the time the I-401 left Ominato, so much of Japan’s sub force had been destroyed that SubRon 1 was the Sixth Fleet’s only full-strength unit. Operation Storm was a brave undertaking, given its limited chance for success. No sacrifice was too great to protect the homeland.
After nearly being sunk in Tsugaru Strait, the I-401 spent most of the next two days underwater. The U.S. Navy wasn’t the crew’s only source of fear. Japanese patrol craft could easily mistake a Sen-toku sub for American and bomb it, so Nambu kept his sub submerged until he was safely out of range of Japan. It wasn’t until July 25 that he felt secure enough to surface in daylight. He then headed south at 19 knots, to make up for lost time.1
The attack plan was straightforward. The I-400 and I-401 would proceed independently of each other, minimizing the chance of both subs being sunk. The I-401 would navigate south past Saipan, Guam, and Truk.2 She would then meet up with the I-400 on August 12 near Ponape Island,3 where they would review the I-13’s and I-14’s aerial intel. The two subs would then proceed to the southern waters off Ulithi, to rendezvous one last time before launching their attack.4 It was a convoluted route, made necessary by U.S. dominance of the Pacific. It would take approximately three weeks to reach Ulithi. If all went well, they’d be ready to strike in mid-August.
Meanwhile the I-400 managed to exit the Tsugaru Strait without being shelled. Kusaka knew the only way to avoid Halsey’s Third Fleet was to head east,5 so he raced to put Japan behind him.
Life aboard the I-400 was routine at first. Kondo even found time to play a Ouija-like game called Kokkuri-san using three hashi (chopsticks) tied together in a tripod. After asking a question, the spirit of a fox assisted in moving the hashi until they pointed to various kanji spelling out an answer. Senior officers disapproved of the game, believing it superstitious, but the younger officers were fascinated by it.
“Are we going to sink?” Kondo asked.
“No,” the fox responded.
“Will we be attacked?”
“
No, you are going home soon.”
The answers were puzzling. Nevertheless, Kondo was relieved to hear they’d survive.6
Once the I-400 cleared the Japanese mainland, Kusaka had to decide how much to travel underwater. Surface cruising was fastest but risked discovery. Traveling underwater was safer but cost precious time. Nambu faced the same dilemma. But the question took on even more importance after both subs encountered a typhoon.
Nambu did his best to power through the maelstrom, but the waves rocked his boat so violently, his crew were thrown from their berths.7 At one point, the sub’s exhaust pipe was swamped, creating so much back pressure, the relief valves sounded like a cannon going off. Fearing the Seiran would be damaged, Nambu was forced to submerge.8
It’s amazing how calm the ocean is 50 feet beneath the waves, and the I-400 subs took full advantage of the peace and quiet.9 When both subs finally surfaced, they found their Seiran unharmed. Unfortunately, they’d also lost valuable time.
A WEEK LATER Nambu moved through the I-401 careful not to bump his head. It may have been the world’s largest submarine, but he still had to duck when climbing through a hatch. That was the drawback of being six feet tall. Nambu spent most of his time in the control room, and since the I-401 was Ariizumi’s flagship, the commander spent his time there as well.
Command and control authority was sacrosanct aboard a submarine. The captain issued orders, and his executive officer made sure the crew carried them out. Nambu was captain of the I-401, so he gave the commands. But Ariizumi’s presence subtly undermined Nambu’s authority. The I-401’s officers knew that many of the orders they received from Nambu originated with their squadron commander—as far as Nambu was concerned, probably too many. It also didn’t help that Nambu was the most junior of Ariizumi’s four sub captains. Additionally, Nambu was the only Sen-toku captain who had not served in Penang with Ariizumi. Even if Nambu had served in the Indian Ocean, it’s doubtful Ariizumi would have changed his command style. It wasn’t his nature.
Operation Storm: Japan's Top Secret Submarines and Its Plan to Change the Course of World War II Page 27