Only search Kamikaze Images


Last Letters of Lieutenant Junior Grade Nobuo Ikebuchi to His Parents

On June 28, 1945, Lieutenant Junior Grade Nobuo Ikebuchi died in a special (suicide) attack at the age of 24 when submarine I-36 launched his kaiten manned torpedo at a large transport ship. On June 4, 1945, submarine I-36 made a sortie from Hikari Kaiten Base in Yamaguchi Prefecture with six kaiten pilots who were members of the Kaiten Special Attack Corps Todoroki Unit. Submarine I-36 headed for a patrol off the Mariana Islands. He was from Hyōgo Prefecture, attended Nihon University (Ōsaka Technical School), and was a member of the 3rd Class of Navy Branch Reserve Students (Heika Yobi Gakusei). He received a two-rank promotion to Lieutenant Commander after his death by special attack.

He wrote the following separate letters to his Father and Mother in June 1945 prior to the departure of submarine I-36 from Hikari Kaiten Base:

Dear Father,

I am going now. I will repay the great favors given to me for so long, and I have chosen the best path. Believing in the indestructibility of the divine land Japan, I smiling will be turned into a bullet. I pray you have good health always. Please take care of Mother and Yuki.

Dear Mother,

I apologize for unexpectedly not being able to meet you due to uncertainty regarding my military assignment right after that time. I believe that you also already are resolved, so please go on living strongly as the mother of a Special Attack Corps member. When you talk about my childhood, you may shed tears once in a while, but I was not a pitiable child as you surely think. I believe that I was the happiest person in Japan. Please do not needlessly worry. I will return again to your side. I am going to live forever in your heart. You were the best mother in Japan for me. However, I believe that I chose the best path. Yuki will be next to you, so I can go with peace of mind. Please live in good health forever.

Please forgive me, Mother. It is the painful thought of that evening when I departed from you in silence. It was me who strongly promised certain victory. It was self-centered me, but just now I am setting forth. I am going. I will go to Yasukuni Shrine [1]. Goodbye Mother, take care.

On June 21, 1945, 17 days after leaving base, submarine I-36 surfaced, and it was determined that all of the six kaiten weapons had mechanical problems. The problems for three kaiten were repaired by June 24, but the other three remained inoperable.

Flight Petty Officer 1st Class Yutaka Yokota (Kamikaze Submarine, 1962, 211-51), one of the six Todoroki Unit kaiten pilots on submarine I-36, writes about the training and mission of the Todoroki Unit in his wartime memoir Kamikaze Submarine. On June 28 at 11 a.m., a large enemy transport was sighted by submarine I-36, and the captain fired a kaiten human torpedo piloted by Nobuo Ikebuchi. The excerpt below from Yokota (The Kaiten Weapon, 1962, 214-7) describes the launch of Ikebuchi's kaiten.

At 11:00 A.M. on June 28, in spite of having had much sleep already, I was sitting in the wardroom, dozing, when I saw a petty officer from the conning tower watch dash past, heading for Captain Sugamasa's cabin.

The enemy! This thought flashed through my mind, and I stirred myself from my sleepiness. The next moment, Captain Sugamasa burst from his cabin and began climbing the ladder to the conning tower. Shortly after, his voice came over the loudspeaker.

"Enemy in sight! All hands to battle stations!"

More orders came, one upon another.

"Stand by for torpedo attack!"

"Load all forward tubes!"

"Stand by for kaiten attack!"

"Number One kaiten pilot, man your weapon!"

Lieutenant Ikebuchi was still asleep. Ensign Sonoda was shaking him by the shoulders. His voice was excited.

"Sir, we have an enemy in sight. You have been ordered to get aboard your torpedo!"

Ikebuchi had his clothes on, but they had been loosened to give him some comfort. He leaped to his feet instantly, fumbled with buttons for a few seconds, then ran toward the stem, shouting back to us, "Take care of everything for me!" He was dirty and sweaty.

1-36 had dipped down after sighting the enemy. Now Captain Sugamasa ordered her up again, to periscope depth. The sound room reported, "Target noises have intensity of two!" as 1-36 began moving in to close torpedo range.

There was trouble in the conning tower, and in the wardroom we could hear part of the conversation. "We are in a bad position," Sugamasa said. "From here it is almost impossible to get a good angle for firing torpedoes. I am going to use the kaiten."

His voice came over the loudspeaker then, telling all hands of this. We could hear him also giving directions to Ikebuchi. "Target is right, ninety degrees. Range, three miles. Target is one ship, a large transport. Speed, twelve knots."

Then: "Kaiten, stand by for launching!"



We could hear Ikebuchi's propeller turning over, as his tie-down clamps snapped open. He moved away. The sound room picked up the noise of his weapon receding. The time was exactly noon.

[paragraph omitted]

Ten minutes passed. He should have nearly covered the distance to the target by this time, I thought. Then, though we were underwater, all of us heard the sound of many guns being fired.

The periscope was raised for a look.

"The enemy has discovered the kaiten!" we heard someone shout. "The enemy has opened fire on it!"

Then came another report from above us. "The enemy ship has changed course! It is running away from the kaiten!"

"Get him, Ikebuchi!" I muttered fiercely to myself, though there didn't seem to be much chance of this. I guessed that Ikebuchi had been sighted when he made his final observation. That's when the enemy opened fire on him. Now he had to dip down again, so the shells could not hurt him. And he could not put up his periscope again, for fear of being seen once more. When his periscope went down, of course, the enemy changed course so as to dodge him. At this moment he might be racing at top speed toward empty ocean, while his target scampered off in another direction altogether.

Still, I had hope. No one I knew operated a kaiten with more skill than this man from Osaka College, except perhaps the dead Furukawa. And, on our last mission, Furukawa chased a destroyer for close to an hour before finally making his hit. I thought Ikebuchi could do the same. In any case, I knew he would never give up until his fuel ran out. The others with me felt the same way.

We kaiten men must have made a strange sight there in the wardroom. We had bunched together tightly and were all in a sort of crouch, facing to starboard, the direction from which the many gun sounds came. We were quiet, listening intently for the great explosion we wanted to hear. Minute after minute dragged by, and when I looked at my watch one time I was startled to see that a full forty minutes had elapsed since Sugamasa had given the command, "Go! " to our chief.

I was getting stiff now, from holding one posture so long, and was straightening up a little when the sound operator screamed, "New propeller noises! Very close! Degree of intensity is four!"

"Down periscope!" shouted Captain Sugamasa. "Emergency dive! Take her to 125 feet! Quickly!"

Soon afterward an enemy destroyer started to drop depth changes to try to sink the submarine that had launched the kaiten. The excerpt below from Yokota (Kamikaze Submarine, 1962, 237-44) picks up the story after submarine I-36 already had suffered over 50 depth charges:

Nevertheless, we were at that moment helpless. Reports throughout I-36 showed we had many leaks. We were losing electrical power, too, as connections were torn loose and instruments shattered by vibration. It would not take many more attacks before I-36 lost this battle. Those last depth charges were not as close as the others. They exploded well below us. But more charges did not have to be close, with the condition we were in. It would not take heavy blows to kill us off. Light ones, near-misses, could finish the job. Their vibrations could crack open our battery banks, loosing poison gas on us, or widen the holes in I-36, letting in sea water. The situation was hopeless.

At that moment Ensign Kuge, who had righted the wardroom sofa and was sitting on it, stood up.

"I will go!" he said.

He went to the conning tower and faced Captain Sugamasa. "My kaiten still works, Sir," he said. "Let me go off and get that destroyer."

"Thank you for your offer, Kuge," said the captain, "but it is impossible. Even if your weapon survived this battering, even if its engine still works, I'm almost certain its electrical equipment won't work. Look at what the depth charges have done to electrical appliances inside this submarine!"

"Let me go, Captain," Kuge kept urging. "Let me go!" He, like I, felt it was preferable to die in battle on his kaiten rather than like a whipped and helpless dog here in the hull.

"But suppose your electrical rudder control is demolished?" said the captain. "You could not possibly steer your kaiten by hand."

Those words! The officers at Otsujima should have heard Sugamasa now. Especially the one who said we should turn over our propellers by hand if necessary. Still, Kuge insisted he should be sent off. "We can't just wait here for the enemy to kill us!" he said.

Perhaps Sugamasa yet had hopes that his skill in maneuvering I-36 would get us out of this trap. Or perhaps that change of heart Sonoda spoke of made him feel his responsibility toward kaiten men more. Perhaps he interpreted Kuge's volunteering as simply a desire to die and prove those Otsujima officers wrong. In any case, he still refused permission.

I-36 Captain Tetsuaki Sugamasa (front 4th from left)
I-36 Todoroki Unit kaiten pilots: (from front left)
Hidemasa Yanagiya, Yutaka Yokota, Ichirō Sonoda,
(from front right) Eizō Nomura, Minoru Kuge, Nobuo Ikebuchi

Kuge's voice rose. He explained that he had plenty of training, and said he was confident he could stop this attacker. They were still arguing when the destroyer came back to make its fifth attack on us. The argument broke off as more depth charges exploded near I-36.

This set slammed the big submarine to one side so hard that every man was thrown to the deck, or against the opposite bulkhead. As the explosions died away I-36 rolled far to one side heavily, recovered slowly, and her fore-and-aft list increased. Our bow was now pointing upward much more than fifteen degrees. Walking through the ship was like climbing the steep side of Fuji-san, the sacred mountain only a few miles from my home in Tokyo.

"All men not actually on watch," called out Sugamasa, "assemble in the forward torpedo room!" Dozens of men passed the wardroom, each one carrying some loose piece of heavy equipment. The stern had to be lightened and the bow made heavier, or else we could slip backward and keep slipping until we were at the ocean's bottom and dead. I joined the crewmen, and so did the other kaiten men. All of us struggled uphill with bags of rice from the submarine's provisions. We worked until we had filled most of the forward torpedo room, but it did not make one bit of difference in the ship's inclination. She still held that steep angle.

Most lights were gone now. In the pale glow of emergency lighting the crew's faces were gaunt and shadowed, smeared with grease and perspiration. So this is the way a submarine dies, I thought. This is how my friends had met their deaths. It was nothing like the attack I had endured in I-47 back near Bungo Strait weeks before. Here we simply sat, taking blow after blow, awaiting the final one that would put an end to us all. There was no respite from the assault. By the time I-36 stopped quivering, the enemy was back again, pouring down his deadly shower upon us.

This time we could plainly make out ourselves that there were two sets of screws above us. That first destroyer now had an assistant. Perhaps it was the one that dodged Ikebuchi's kaiten. Where was Ikebuchi now? Dead, no doubt. His fuel must have long since run out. He had probably used his short sword to commit seppuku. We had heard no distant explosion, as there would have been if Ikebuchi used his inside switch. He must have continued on until his fuel was exhausted, then disemboweled himself. What an end for a man so brave!

Each depth charge explosion made me think it would be the last one, especially when those two destroyers crisscrossed above us in the sixth attack. They knew exactly where we were. So far as they were concerned, I am sure, it was simply a matter of time. All they were waiting for was the telltale bubbling of black oil that would show our side was ripped open and that we were sinking. It puzzled me how we could take the punishment dealt out so far and survive.

Then came the seventh attack. Another dozen or so depth charges plummeted down toward us. They, too, exploded below us. This was luck. Had they realized what Captain Sugamasa was doing, the enemy destroyer commanders would set their depth charges for shallower explosions. On our deck, in the kaiten warheads, were fifteen thousand pounds of high explosives. If one of the warheads went, we would be finished. So, perhaps, would one of those destroyers, if it were overhead at the time. Its bottom could be ripped out.

Over ninety depth charges had come down at us by that time. Still I-36 staggered on. I had reached the point where every nerve end was ragged. I quaked constantly, and so did others I could see. In my palm I held a celluloid container of potassium cyanide. I was sure the enemy would get us. Once they made their sought-after direct hit, and water came rushing into out hull, I was going to swallow the container's contents. I could not bear to think of death by drowning, or suffocation.

It was now 3:00 p.m. We had been subjected to seven separate depth charge attacks in two and one-half hours. Captain Sugamasa's voice came over the loudspeaker. It was desperate-sounding.

"Kaiten men, get ready! Man kaiten Number Five and Number Three!"

Kuge was getting his wish at last. Yanagiya was also being sent to his weapon. I shouted, "Good luck!" as they struggled along the slanted deck to their access tubes. I wasn't sure whether Captain Sugamasa put any hope in them, or whether he was simply giving them their wish, to die as kaiten men should. Maybe he knew his own life was short, and wished to close it with a grand gesture.

Mechanics had checked the kaiten. The electric rudder control was inoperative in each one. They were dry, though, a miracle after all that depth-charging. But Kuge and Yanagiya would have to employ manual rudder control. It would be very difficult for them to maintain a course for the enemy.

All of us had practiced using manual control of rudder in training. It made a kaiten zigzag terribly. If those destroyers were not close by when our kaiten were launched from I-36, there would be little chance of hitting them. The run-in would have to be short for success to be achieved. The captain knew of this. It had made him reluctant to give permission when Kuge first asked for it, hours before. But now one last frantic effort had to be made to get the monsters off our backs.

There were no telephone connections to either kaiten. Both had snapped loose during the attacks from above. Kuge and Yanagiya would have no information from the conning tower on which to act. One hammer blow on the hull would be the signal for Yanagiya to go off. Two hammer blows would be the signal for Ensign Kuge.

Yanagiya's clamps were loosened, and a crewman swung a big hammer with all his might against the hull. Then we waited. A second passed. Then another. Then, welcome sound, we heard Yanagiya's propeller spin rapidly. He moved away, and was off in search of the enemy.

How would he handle his kaiten, I wondered? Would his meters and gauges give proper indications? At this moment we were at the 215-foot level, having slid down to it in spite of every effort made within the submarine, including the carrying of rice bags forward. Yanagiya would have to climb almost vertically if he were to remain near I-36's location and ambush the enemy.

Yanagiya's engine sound was still audible when a second crewman struck the forward part of our hull twice. We heard the securing bands for Kuge's kaiten snap open and fall on the deck, but there was no sound from his engine. Would he simply float to the surface? If so, the enemy would machine-gun his weapon. Could we survive the mighty explosion of his warhead if it went off directly above us? These questions passed rapidly back and forth among the group of men near me, and one said, "What difference? If those kaiten are lost, we are lost too!"

We waited, breathless, wondering what would happen. Then, about thirty seconds after Kuge's hold-down clamps had snapped, we heard a familiar sound. His engine had started! What a wonder! the kaiten was an unpredictable thing, I thought. In spite of scrupulous maintenance, those engines often did not start at Hikari and Otsujima. Now we had two weapons that had been exposed to the sea for twenty-five days, and had been beaten badly by many depth charges. Yet they worked. Some things are simply unexplainable.

The next few minutes were very quiet. The kaiten engines faded, and no destroyer propellers could be heard. Another ten minutes passed. It was almost fifteen minutes since Yanagiya had been released. The two men must be steaming toward their targets, those two destroyers.

Quite suddenly we heard several small explosions, quite a ways off, followed by a giant one. A kaiten had detonated!

Hoarse cheers rose from our tired throats. "They did it!" we shrieked to one another. "One of them got an enemy!" A charge of 3,000 pounds had gone off, and we were sure in our minds one of the hunters above had been destroyed. Tears of sorrow and joy for my comrades welled into my eyes. One of them, at least, had fulfilled his destiny.

What of the other? Our sound room reported that only one destroyer could now be detected. He seemed to be heading toward the spot where the big explosion had occurred. He was dropping depth charges, the sound operator said. They were very far away from us.

More depth charges were fired. We in the hull could make them out faintly. We decided that this remaining enemy ship was pursuing the second kaiten. One of our friends was saving our lives for us. He was drawing off an attacker so I-36 could make an escape. How the enemy must have been surprised, we told one another. At one moment he was thinking he had a sure kill of a submarine. He was dropping depth charges as a hunter fires cool shots at fleeing game. The next moment he was faced with two giant, high-speed torpedoes, seeking to kill him instead.

More time passed. The sound of enemy screws disappeared completely. And no more depth charges could be heard. Both the kaiten and that destroyer must be somewhere far beyond the horizon. Captain Sugamasa changed course and crept away as quietly as he could. A returning enemy would have practically no chance of finding us now.

Thus did Petty Officer Yanagiya and Ensign Kuge save our submarine. Which one had hit the destroyer, and which had played the decoy? Had it been Kuge whose explosion we had heard? Had the shy Osaka man, who had written to his brothers and sisters daily, killed off that threat? How fierce had been his determination, this man who had suggested to Captain Sugamasa the idea of firing kaiten from the depths! How paradoxical did his behavior seem to people other than kaiten pilots, who knew him best? Kuge was so shy and bashful that he had to pretend he had a sweetheart when other men discussed the subject. On one occasion he showed us a picture of a lovely young girl in her school uniform, and told us it was his lover's. It was not until much later that we found out it was really a picture of his sister. Had this modest, retiring person been the one who'd struck that mighty blow?

Or was it Yanagiya, who had to stay at home, working in a fishery, while the rest of Japan's young men fought on far shores and distant seas? Growing furious at each bad turn in the war, he had finally overcome his parents' opposition and convinced them he had to fight for his country, even though they had already given one son in death. What a warrior he had been! At Tsuchiura this short, stocky man from the north had proven his aggressive spirit beyond doubt. A wrestling party was held, with 100 cadet pilots ordered to fight. Yanagiya was the only survivor, defeating all others after they in turn had defeated their opponents. More than a score of cadets were sent tumbling by his thick arms and body. Had it been this merry, honest man, who made no pretense about his being from a humble home, who had driven into the enemy's heart? Or had he foregone glory, to draw the second ship away and aid us to escape?

We would never know.

Captain Sugamasa spoke to us over the loudspeaker, his words interrupted by sobs.

"Attention, all hands!" he said. I wish everyone to make their best efforts to repair the damage done to us. Ensign Kuge and Petty Officer Yanagiya have just died heroes' deaths, as did Lieutenant Ikebuchi. Do not let them die in vain! We will return to the base as quickly as we can, once the damages are repaired. We will refit, and come out to fight again. We will take our revenge for these three brave comrades. I give you my word I will lead that fight myself!"

All around me men were weeping. The only clean spots on their dirty, grease-smeared faces were where tears  ran down them. I had wept on occasion before, but this time it was different. These were tears of true sorrow. They came up from the center of my being. This time I was not sorry for myself. I grieved for those brave men, and their honest, heroic acts. I actually wanted to return to port. I wanted to go to Hikari, get a new kaiten, and came back out with Sugamasa after the enemy.

Writings translated by Bill Gordon
February 2024

The letters come from Mainichi Shinbunsha (1967, 128). The biographical and mission information of submarine I-36 come from Konada and Kataoka (2006, 249-58, 374-5), Mainichi Shinbunsha (1967, 128), Mediasion (2006, 62, 85), and Yokota (The Kaiten Weapon, 1962, 214-7; Kamikaze Submarine, 1962, 211-51). The two photographs come from Kataoka (2006, 250) and Mediasion (2006, 62).


1. Yasukuni Shrine in Tōkyō is the place of enshrinement for spirits of Japan's war dead.

Sources Cited

Konada, Toshiharu, and Noriaki Kataoka. 2006. Tokkō kaiten sen: Kaiten tokkōtai taichō no kaisō (Special attack kaiten battles: Kaiten special attack corps leader's reminiscences). Tōkyō: Kōjinsha.

Mainichi Shinbunsha, ed. 1967. Ningen gyorai: Kaiten tokubetsu kōgekitaiin no shuki (Human torpedo: Writings of Kaiten Special Attack Corps members). Tōkyō: Mainichi Shinbunsha.

The Mediasion Co. 2006. Ningen gyorai kaiten (Kaiten human torpedo). Hiroshima: The Mediasion Co.

Yokota, Yutaka, with Joseph D. Harrington. 1962. The Kaiten Weapon. New York: Ballantine Books.

________. 1962. Kamikaze Submarine. Originally published as The Kaiten Weapon. New York: Nordon Publications.