Ships
- IJN Tenryu Captain from 5 June 1942 · Relieved on 5 December 1942
5 June 1942 is the date the later lists use for the start on Tenryū. She was sunk thirteen days after he left, under another captain of the same academy class.
The characters are 浅野新平. Nishida’s class-45 sheet prints the reading あさの しんぺい and romanizes it Asano, Shinpei. The Japanese Wikipedia article uses the same furigana. American captions from the Guam trials print Shimpei. That is the same しんぺい, not a second officer. Shinpei is the reading the Japanese table prints. One Chinese-language captain list uses the older form 淺野. The sheets and the class tables used here print 浅野.
He is not Asakura. Asakura is 朝倉豊次, Naval Academy class 44, born in 1894 in Toyama, captain of Takao and later of Musashi, and he died in Japan in 1966. He is not Aruga. Aruga is 有賀幸作, class 45 with Asano, fifty-eighth of eighty-nine, born in 1897 in Nagano, and he was killed aboard Yamato on 7 April 1945. Asano was fiftieth of the same eighty-nine. The compiled sheet ends him with 刑死, death by sentence, on 31 March 1949. The ships do not overlap, and the deaths do not either.
He was an officer of the Imperial Japanese Navy. The records say the same thing.
Origins
He was born on 1 December 1895. Nishida’s class table and Niehorster’s Etajima name index both give the prefecture only: Ibaraki. A Japanese Wikipedia article adds Shimotsuma city, and adds that he finished Shimotsuma middle school, the school that is now Shimotsuma First High School. Both of those sentences are marked on the article as needing a citation. No birth register was opened. A father’s name was not found. Shimotsuma is not used here as fact.
The same article calls the zoologist Iwakawa Tomotarō his father-in-law, and points the relationship at Fukukawa Hideki’s Nihon Kaigun Shōkan Jiten (Dictionary of Japanese Navy Flag Officers), page 17. The dictionary itself was not opened. Iwakawa’s own Wikipedia article, in an unfootnoted family list, names a fourth daughter, Sumi, born in 1900, as the wife of the Naval Academy graduate, rear admiral, and imperial aide Asano Shinpei, and names a grandson, Asano Hiroshi, born in 1930, a graduate of Tokyo Higher Normal School and later professor emeritus at the University of Tsukuba. A mirror of Asano’s article calls Hiroshi the eldest son. No family register was seen. The marriage and the son are what those articles print. They are not a register entry, and nothing found here says what Sumi or Hiroshi knew, or when they last saw him.
Iwakawa died on 2 May 1933, a zoologist of the Morse generation at Tokyo Imperial University, an honorary professor at the women’s higher normal school. If the relationship is right, the father-in-law was already dead before Asano went to sea with a prince, and long before the war. No letter between the houses was found.
Formation
The years from Etajima to the first staff shore job are a table, not a life. No letters, no fitness reports, and no photograph with a known photographer were found for the peacetime officer. Nishida’s class-45 sheet is the only continuous account. It is a private compilation. It is used here where later documents and other tables confirm the man, and it is labeled where they do not. The appointment gazettes for these dates were not opened.
On that sheet he left the Naval Academy on 24 November 1917, a midshipman, fiftieth of eighty-nine in the 45th class. Niehorster’s class list gives the same graduation day and the same class size, and it prints the kanji 浅野新平. The graduation gazette itself was not opened. Fiftieth of eighty-nine is the lower middle of the list. The sheet does not name his midshipman cruise ship. Classmates on the same page are assigned that day to Iwate or Asama. His line says only that he graduated. The blank is in the compilation. It is not proof that he had no ship.
He was commissioned ensign on 1 August 1918 and joined the battleship Fusō. On 1 December 1918 he went to the basic course at torpedo school, and on 23 May 1919 to the basic course at gunnery school. From 1 December 1919 he was in the destroyer Matsukaze. He was promoted lieutenant junior grade on 1 December 1920. The table gives him no new ship that day.
On 1 January 1922 he was an acting division officer and instructor in the Maizuru barracks. On 20 July 1922 he joined the destroyer Sumire, and on 10 February 1923 the destroyer Kuwa. He was promoted lieutenant on 1 December 1923 and entered the higher course at gunnery school. The next line is 1 December 1926, division officer in the battleship Nagato. Three years sit between those two dates with no order printed. A higher gunnery course did not last three years. The intervening billets are missing from the sheet, and they were not found elsewhere.
On 10 December 1928 he was gunnery officer and division officer of the carrier Hōshō. He was promoted lieutenant commander on 30 November 1929. From 15 November 1930 the sheet puts him in three places at once: instructor at the paymaster school, instructor at the naval medical school, and division officer in the Yokosuka barracks. It does not say what he taught. The medical-school line is only a billet. It is not evidence about anything he did fourteen years later.
On 15 November 1932 he was attached to the Shanghai Special Naval Landing Force, as a division officer, and attached as well to the staff of the Third Fleet. He stayed until 20 October 1933, when he was sent to Yokosuka Naval District. The fighting of the first Shanghai incident had ended in May 1932. He arrived in November. The table is a garrison attachment after the truce, not a battle. No action report with his name was found.
On 1 November 1933 he was appointed aide to an imperial prince, 朝融王, Prince Kuni Asaakira, and attached to the Naval General Staff. Asaakira was himself a naval officer, Naval Academy class 49, later a vice admiral. From 15 November 1933 the aide billet was concurrent with duty aboard the cruiser Kiso. From 19 July 1934 it was concurrent with the cruiser Yakumo. On 1 August 1935 he was still the prince’s aide, and again a General Staff attachment, until 15 November 1935. The sheet does not say whether he lived in the prince’s household or simply stood the sea duty the prince was assigned. No remark, no letter, and no court diary was found. The posting is the unusual thing in an otherwise ordinary gunnery career: for two years his name sat next to a prince’s, and the Navy still sent him to sea.
On 15 November 1935 he was promoted commander and made executive officer of the cruiser Tama. On 1 December 1936 he went to the personnel section at Kure. On 15 November 1939 he was executive officer of the heavy cruiser Suzuya. Combined Fleet’s Tenryū record, when it reaches 1942, still identifies him as Suzuya’s former executive officer. He left her, on the sheet, when he was promoted captain on 15 November 1940. Ten days later, on 25 November 1940, he was chief of the first section and of the second section in the Yokosuka personnel department. He was a new captain in a shore personnel office, in the year before the Pacific war. Suzuya’s later wartime cruises are not his. He was off her before they began.
No decoration is entered against his name on the class sheet. Classmates on the same page carry the Order of the Golden Kite in the margin. His margin is empty. That is the compilation’s silence, not a search of the award gazettes. The gazettes were not opened.
War years
He left the Yokosuka personnel office on 15 May 1942 and was attached to Yokosuka Naval District, the usual holding billet. On 5 June 1942 he was appointed captain of the light cruiser Tenryū. Nishida, the Japanese Wikipedia captain list for the ship, and Combined Fleet’s tabular record all give that day. The appointment sheet was not opened. Captain Gotō Mitsutarō, who had had her since 28 August 1941, went to the staff of Kure. The man who would sink with her was not yet in the order book.
Tenryū was an old ship, completed in 1919, a small cruiser built to lead destroyers. By June 1942 she had already been through Wake, Rabaul, Lae, and the Coral Sea operation, all of it under Gotō. Asano did not command any of that. What he took, on the movement record compiled by Hackett and Kingsepp, was a ship in dock. She had reached Maizuru on 23 May 1942. On 3 June she was in No. 3 drydock for more anti-aircraft guns, a degaussing coil, and armor over the torpedo warheads. He became captain on the 5th, while she was still on the blocks. She undocked on 13 June. On 15 June she left Maizuru for Truk. The record brings her in on 23 June. The next operation line has her leaving Rabaul on 20 July. The table, as printed, does not show the passage from Truk down to Rabaul. That gap is in the compilation.
From there until 5 December the ship’s movements are the only account of how he spent the war at sea. They are a secondary reconstruction, drawn on war diaries the authors name in places and do not quote here. The Cruiser Division 18 diary was not read for this essay. Nothing in the movement record quotes him. The captain is present as the man whose dates bracket the cruise.
On 20 July 1942 Cruiser Division 18 left Rabaul for Buna with a minelayer, destroyers, and three transports. The troops went ashore on the 21st. American bombers sank one transport the next day. Tenryū was back at Rabaul on the 24th. It was a landing, not a battle he is recorded as having fought.
The battle was Savo. On 7 August the Americans landed on Guadalcanal. That day Tenryū left the Möwe Passage with Yūbari, the four heavy cruisers of Cruiser Division 6, Chōkai, and the destroyer Yunagi, and came down the Slot. In the night action of 9 August, the compiled record says Tenryū hit the American heavy cruiser Quincy with two torpedoes. Quincy sank, with Astoria, Vincennes, and HMAS Canberra. Tenryū was hit, the record says probably by Chicago. Twenty-three of her men were killed. The record does not say who gave the order to fire, or what the captain did in the minutes the torpedoes ran. It says the ship hit, and the ship was hit, and twenty-three men died while he was her captain. The next morning the force retired. Tenryū went back toward Rabaul. The heavy cruisers went toward Kavieng, and Kako was torpedoed and sunk on the way.
The rest of his cruise was the Solomons as a ferry and a rescue ship. On 17 August he took a convoy of base supplies to Basuba. At the end of the month Cruiser Division 18 covered the landing of the Kure 5th Special Naval Landing Force at Milne Bay, and then the landing of the Kure 3rd. The operation failed. On 4 and 5 September the cruisers went back into the bay and took the landing force off. The record’s figure for the whole evacuation by the division is 1,318 men. On 11 September Tenryū went out to look for survivors of the destroyer Yayoi and found none.
On 2 October 1942, at Rabaul, six B-17s hit her. One bomb opened a hole about sixteen feet long in the port side of the upper deck aft. Splinters wrecked the after superstructure. Twenty-two men were killed and twenty-six wounded. The repair ship Hakkai Maru patched her. The record says the repairs were finished on 20 October. He was still the captain. The ship was not sent home.
She made three night runs to Guadalcanal in the first ten days of November, from Shortland, with food, ammunition, and men of the 38th Division, unloading after dark off Tassafaronga and Cape Esperance and leaving before morning. On 6 November she was used, for the moment, as flagship for Rear Admiral Takama Tamotsu of Destroyer Squadron 4. On 13 and 14 November she went down again with Nishimura’s bombardment unit and with Mikawa in Chōkai. American aircraft sank Kinugasa. A dive bomber crashed into Maya. The record says Tenryū was not damaged. She was back at Shortland on the 15th, at Rabaul on the 23rd, and the division flag returned to her.
On 5 December 1942 Captain Ueda Mitsuharu, class 45 with him, former captain of the destroyer Wakatake, was appointed in his place. Asano was attached to Yokosuka. The sheet does not. He had had her for six months: a dockyard, Buna, Savo, Milne Bay, a bomb at Rabaul, three nights off Guadalcanal. Forty-five of his crew were dead by the count in that movement record, twenty-three at Savo and twenty-two under the B-17s, and that count is the compilation’s, not a casualty list read from the ship.
He was not aboard when she sank. On 18 December 1942, under Ueda, off Madang, USS Albacore hit her with two torpedoes. She sank that night. Twenty-three more men were lost. Ueda survived. Removing Asano from the story of the sinking is not a kindness to him. It is the date. The man who had commanded her through the worst of the year was already on a Yokosuka order.
On 20 December 1942 the sheet makes him chief of the 1st Supply Department and of the 2nd. On 10 January 1943 the second of those jobs drops away and he remains chief of the 1st. The sheet does not say where the departments were. No diary of that year was found. He was a captain at a desk, or at a depot, for thirteen months. The sea command was over.
On 28 January 1944 he was attached to the 6th Base Force. The JACAR unit glossary’s commentary says that force was formed in January 1941, reached Jaluit in March 1941, and that most of it died at Kwajalein on 6 February 1944. The same glossary’s “city” field says Truk, which does not match the commentary. Asano’s attachment runs from 28 January to 20 February, across that 6 February date. An attachment order is not a landing. The sheet does not say he was on Kwajalein, and it does not say he was not. The American invasion of the atoll began at the end of January. If he had been with the main body, the later record of a living captain at Truk would need an explanation the table does not give. The honest line is that the order exists and his whereabouts that week were not found.
On 20 February 1944 he was appointed commander of the 41st Guard Unit. The JACAR glossary, citing a 1985 Ministry of Health and Welfare pension survey (JACAR C08030492200), says that unit was formed at Truk on 10 April 1942, under the 4th Base Force of the 4th Fleet, to defend its sector and to support other forces, and that it ceased on 2 September 1945. The carrier raid that broke Truk as a fleet base, Operation Hailstone, was 17 and 18 February 1944. His appointment is two days after the bombs. The sheet does not say whether he was already in the lagoon or came in afterward to a base that was no longer a base.
From 10 March 1944 he was also chief of the 4th Transport Department. From 15 July he was also commander of the 85th Submarine Base Unit. From 3 August he was also, again, chief of the 1st Supply Department. Four titles, one bypassed atoll. Kitabatake’s end-of-war flag-officer table still has him there: Rear Admiral Asano Shinpei, class 45, commander of the 41st Guard Unit. He was promoted rear admiral on 1 May 1945, on the sheet, with no new duty. The rank arrived in the last summer of the war, while he was still the guard commander. Classmates who had finished higher in the class had been rear admirals since 1943. The date is the Navy’s. It is not a judgment written on the sheet.
The 4th Fleet’s commander in chief was Vice Admiral Hara Chūichi. The chief of staff, from the same class table, was Rear Admiral Sumikawa Michio, fourth in the class of 1917. They were on the same atoll. What Asano said to either of them was not found in a fleet diary read here.
The cost
The cost is not Savo. He survived Savo, and the bomb at Rabaul, and the ship’s sinking under the next man. The cost is a dispensary on Truk in June 1944, and a gallows on Guam in 1949.
What follows is not a judgment read from the commission’s transcript. The Navy Judge Advocate General case file was not opened. The account is the one the Japanese Wikipedia article on the naval vivisection case gives, and that article is a synthesis of Iwakawa Takashi’s reporting in the magazine Gendai in February, March, and April 1982, of a 1995 book by the same author, of a 2010 study by Inoue and others, and of a page in the Tokyo Trial Handbook. Those books and articles were not read. Where English summaries disagree with that synthesis, the disagreement is kept.
The article’s June incident is this. Around 20 June 1944, in the dispensary of the 41st Guard Unit, medical officers of the unit cut open the chest, the abdomen, and the scrotum of one American prisoner, as a medical experiment, and then told noncommissioned officers to kill him. The prisoner was not yet dead. They took him behind the dispensary, beheaded him, and buried him. At the same time another American prisoner was killed with bayonets. The article treats this as a separate case from the killings and experiments at the 4th Naval Hospital on the same atoll, for which the hospital director, Iwanami Hiroshi, was later hanged. Asano was not that hospital’s commander. He was the guard unit’s.
Ten men of the 41st Guard Unit were tried for the June case, the article says: Asano, the unit’s medical chief Ueno, and eight others. Asano and Ueno were sentenced to hang. Four others were sentenced to life. Two noncommissioned officers who had carried out the beheading and the stabbing were also sentenced to hang at the first judgment, and on review those two sentences were reduced to life. At the trial, the article says, Asano and Ueno each claimed the other had led the thing. After the first judgment Asano filed a statement of grounds for appeal. He said the judgment rested on a mistake of fact. A further hearing was held. The claim was not accepted. Both death sentences were confirmed.
An English summary by Jeanie M. Welch, in the International Journal of Naval History in 2002, citing a 1994 magazine piece by Paul Addison rather than the case file, tells the June case more narrowly and puts the order in Asano’s mouth. Five American airmen were shot down over Truk. Two were captured. Ueno, commanding the first-aid unit, was ordered by Asano to “dispose of the two persons.” Ueno operated on one of them. Welch’s defense summary for Ueno is the defense Ueno actually ran: no jurisdiction, vague charges, superior orders, a medically justified operation. Welch does not summarize a defense for Asano beyond the shared conviction. Welch dates both hangings to 31 March 1947. That year does not match the Japanese service compilation.
Guampedia’s account, by Donald R. Shuster, convicts “Rear Admiral Shimpei Asano” and “Surgeon Commander Chisato Ueno” of torturing and murdering four American prisoners “at Chuuk and Kwajalein,” and says evidence showed that Iwanami, Asano, and Ueno had allowed or conducted medical experimentation and mutilation. The number four, and the addition of Kwajalein, are not in the Japanese article’s June narrative, which is two prisoners on Truk. A secondary execution blog, citing the National Archives case files and a book on the Truk wrecks, says Asano was hanged for the same two Truk murders as Ueno and, in a footnote, for two further prisoners killed at Kwajalein. The case file those sentences point at was not opened. Kwajalein is not adopted here. It is a conflict.
A University of Guam catalog record describes a Navy photograph of six defendants “on trial” for crimes against American prisoners on Truk. In the front row it names Rear Admiral Shimpei Asano and Lieutenant Commander Shohichi Nadase. Behind them it names Surgeon Commander Chisato Jeno — Ueno, misread — and a lieutenant junior grade, a surgeon ensign, and a petty officer. The catalog date is 26 September 1949, and the item date is September 1949. If he was hanged on 31 March 1949, that date cannot be the date of a trial photograph of a living man. The catalog date is not usable. The names are. The photograph itself was not examined.
Nishida’s sheet ends on 31 March 1949 with 刑死, and the age 53. The Japanese biographical article, citing Fukukawa’s dictionary, gives the same day and places the death on Guam. Niehorster’s name index says he “died March 3, 1949,” which loses both the day and the fact that it was a sentence. Welch’s 31 March 1947 loses the year. The date used here is 31 March 1949, because the Japanese service compilation and the dictionary tradition agree on it, and because the execution narrative that describes the evening also uses 1949. It is not a death certificate. The certificate was not seen.
The execution blog, citing a pamphlet on military executions and a Truk book, describes the evening of 31 March 1949: Ueno hanged shortly after eight, and Asano a few minutes before him, rank going first. The heights and the minutes in that paragraph are the blog’s, from those books. They were not checked against a provost marshal’s log. Guampedia says the senior officers hanged on Guam, Asano among them, were buried in unmarked graves on American military land. That sentence covers seven men. No grave register was opened.
No word of his at the foot of the gallows was found. The only words the secondary record attributes to him are the ones in the courtroom: that Ueno, not he, had led the June killings, and that the first court had the facts wrong. The courts did not accept that. What he believed, and what he was willing to sign, are not the same thing, and the papers that would separate them were not read.
After
There is no retirement line on the sheet. There is no demobilization date for him, as there is for classmates who went home to the reserve in the autumn of 1945. The guard unit’s glossary entry ceases on 2 September 1945. His own name continues, in the only sources that carry it past the surrender, as a defendant and then as a man who was hanged.
The Japanese Wikipedia article says that on 31 January 1948 he was provisionally designated under the public-office purge, and it cites page 108 of the purge roster compiled by the Prime Minister’s Agency and published in 1949 (National Diet Library, NDLJP 1276156). That page was not opened. If the citation is right, the Japanese government listed him for exclusion from public life while the American case was still running. It is a bureaucratic line. It is not a life in Japan. No occupation, no address, and no return home were found, because the record does not show a return.
What the family articles leave on the other side of the date is a wife, Sumi, and a son, Hiroshi, born in 1930, who if the article is right became a professor. They are names in an unfootnoted list. Nothing found here says whether they received a body, a letter, or a pension, or whether Hiroshi ever wrote about his father. Iwakawa, the father-in-law, had been dead sixteen years. The house Asano married into was a scientist’s house. The Navy’s sheet does not mention it.
He was fifty-three. He had been a midshipman at twenty-one, a gunnery lieutenant on Nagato and Hōshō, a prince’s aide, a heavy cruiser’s executive officer, a personnel captain, and for six months in 1942 the captain of an old light cruiser that fought at Savo and buried its dead at Rabaul. The Navy made him a rear admiral on a bypassed island. An American commission on Guam held him responsible for the killing of prisoners in his guard unit’s dispensary, he disputed the facts, and the dispute failed.