By Emilia Wellesley · Published May 6, 2026 · Updated May 6, 2026
The Honjō Masamune is the most famous lost sword in Japanese history. Forged around the turn of the fourteenth century by Gorō Nyūdō Masamune (c. 1264–1343), it served as the hereditary blade of the Tokugawa shoguns for more than two centuries before disappearing in January 1946, days after the family surrendered it to a Tokyo police station under Allied disarmament orders.
How a Kamakura blade became a Tokugawa heirloom
Masamune worked in Kamakura, the political seat of the Hōjō regents, during the last decades of the Kamakura period. The standard chronology, drawn from the Edo-era reference Kotō Meizukushi Taizen, places his active years between roughly 1288 and 1328 and his life from 1264 to 1343 [1]. He learned under Shintōgo Kunimitsu, probably also under Saburō Kunimune, and either inherited or was adopted by the smith Yukimitsu. From these teachers he carried forward what historians of Japanese metallurgy now call the Sōshū-den, the Sagami school, named for the province whose forges produced it.
What distinguished his blades was not ornament but the steel itself. Sword scholars describe the Masamune surface as silky itame, a wood-grain pattern in the folded steel, with a temper line of bright nie crystals scattered like frost along the cutting edge. The Nihon Bijutsu Tōken Hozon Kyōkai (NBTHK), the modern body that authenticates Japanese swords, recognizes only about eighty-one blades attributed to Masamune across all categories, including nine designated Kokuhō, or National Treasures [2]. Out of a working life of forty years, that is a small surviving canon, and most of those blades carry no signature. The reason is procedural: in the master’s circle, attribution rested on the eye of later appraisers, especially the Hon’ami family of Kyoto, whose gold-inlaid certifications still serve as a backbone of nihontō scholarship.
Honjō Shigenaga and the naming of the blade
The sword acquired its proper name from a battlefield. The general Honjō Shigenaga (1540–1614), a retainer in the long Uesugi-Takeda contests of the late Sengoku period, took the blade in 1561 from a defeated rival named Umanosuke. Shigenaga survived the encounter, the blade did too, and from that moment the sword carried the Honjō name [3]. In 1592 the blade passed to Toyotomi Hidetsugu at Fushimi Castle, reportedly traded for thirteen large gold coins, and from there to his uncle, the regent Toyotomi Hideyoshi. After Hideyoshi’s death the sword moved to Tokugawa Ieyasu and joined the bakufu’s inner armory. It remained with the Tokugawa house, including branches descended from Yorinobu and Ietsuna, for the better part of two and a half centuries.
The 1939 designation and what it told scholars about the blade
By the 1930s the Honjō Masamune was already understood inside the small world of nihontō scholarship to be the finest known Masamune. Around 1937 the sword scholar Honma Junji (1904–1991), who later signed his appraisals with the pen name Kunzan, examined the blade at the residence of Tokugawa Iemasa during the preliminary survey for state designation [4]. Honma was no peripheral figure. After graduating in 1928 he had taken a researcher’s post at the National Treasures Survey Office of the Religious Affairs Bureau, and his judgments effectively built the modern catalog. On 27 May 1939 the sword was elevated to Kokuhō under the prewar 1929 Cultural Property law, the highest classification then available [5].
The designation matters for two reasons. It anchors the blade’s existence in the documentary record at a known address as recently as the late 1930s, and it tells us a competent specialist had already taken the kind of close measurements and rubbings that would, in a less catastrophic decade, have given posterity a forensic baseline. Honma’s notebooks survive. The blade itself does not.
December 1945: the surrender at Mejiro
When General Douglas MacArthur’s headquarters issued the disarmament directives that followed the September 1945 surrender, the orders did not at first carve out an exception for art swords. SCAPIN 181 of 24 September 1945 instructed the Japanese government to collect and surrender all firearms, swords, bayonets, and daggers from military personnel, civilians, and public officials, with the actual collection coordinated through local police stations [6]. By 1946, more than three million swords had been forfeited or destroyed. The directive treated a mass-produced wartime guntō the same way it treated a fourteenth-century Sōshū blade.
Tokugawa Iemasa, head of the main Tokugawa line and a former diplomat, decided the family should comply visibly and immediately. In December 1945 he handed fourteen blades, including the Honjō Masamune, to the Mejiro police station in Tokyo [7]. He was, by every account, trying to set an example for other noble families and to spare the collection from being scattered through quiet trades or pilferage. The choice was reasonable. It also placed the most important Masamune in Japan inside an evidence chain operated by exhausted Japanese policemen and overstretched American occupation officers, working without a shared written language and without uniform property-receipt procedures. What happened next has frustrated researchers for almost eighty years.
The receipt to “Sgt. Coldy Bimore”
On 18 January 1946 the Mejiro police released the Tokugawa swords to a representative of the Foreign Liquidations Commission of AFWESPAC, the Army Forces, Western Pacific. The receipt named the recipient as Sergeant Coldy Bimore, sometimes rendered Coldy Bemore [8]. In later decades, when collectors and Japanese cultural officials began to look for the blade, they discovered something inconvenient. No soldier by that name appears in U.S. military service records of the period. Folklore eventually attached him to the 7th Cavalry Regiment, but no roster supports the attachment.
The strongest reconstruction belongs to researchers who treated the name as a transliteration problem rather than a forgery. The phonemes “Coldy Bimore” map cleanly onto a real American name written in Japanese police hand: Cole D. B. Moore. A Technician 4th Grade, T/4, wore three chevrons with a T beneath them and was routinely addressed as “Sergeant” by anyone unfamiliar with Army insignia. A Japanese officer at Mejiro recording the recipient phonetically and in haste could plausibly produce “Sergeant Coldy Bimore” from “T/4 Cole D. B. Moore.” The hypothesis is unproven. It is also the only one that makes the receipt readable.
After January 1946 the trail goes cold. The FLC’s mandate covered the disposal of surplus property abroad, and surrendered swords moved through warehouses, dumps, and personal souvenir kits in numbers that defeated any inventory. Most blades collected under the early sword hunt orders were destroyed: melted for scrap, dumped at sea, or piled in warehouses like the one at Akabane in Tokyo where a few were eventually rescued [9]. A smaller and more fortunate set, including hundreds of art swords screened by Honma Junji and his colleagues, were preserved when the policy shifted later in 1946 to recognize traditional blades as cultural property rather than weapons.
What probably happened to the blade
No primary document confirms the Honjō Masamune’s fate after the Mejiro handover. Three reconstructions remain in play, and a careful reading of the procedural record favors none of them decisively.
The first is destruction. If the blade entered the general FLC sword pool in the first weeks of 1946, before any policy carve-out for art swords took effect, it could have been melted, dumped, or buried with the bulk of confiscated weapons. Researchers who lean toward this account note that the sword’s National Treasure status would not have protected it: the Mejiro receiving officers, working in Japanese, are unlikely to have communicated the designation to American supply staff working in English, and the blade was not signed in a way that would announce itself to a non-specialist. The second reconstruction is private retention. American officers were eventually permitted to keep surrendered swords as souvenirs, and a recipient who recognized what he held, or who simply liked the blade, could have shipped it home in a footlocker without obvious paperwork. Specialists have sometimes received tips that match this scenario, including occasional rumors of a Masamune in a private American collection, but none has produced a verifiable blade. The third reconstruction is administrative limbo. A small number of confiscated swords sat in warehouses for decades before being identified, and the Honjō Masamune could in principle still rest in a forgotten stockpile or a private estate inherited by descendants who have no reason to recognize what they own.
Each reconstruction explains some of the evidence. None explains all of it. What ought to be a search problem with a clean documentary trail has remained a mystery because the trail breaks at the exact procedural seam where an exhausted Japanese police bureau, an under-resourced American disposal commission, and a non-existent sergeant met for an afternoon at Mejiro and left no usable receipt.
What the loss means for Japanese sword scholarship
The procedural mystery has tended to overshadow the cultural one. The Honjō Masamune was not simply a famous blade. It was, in Honma’s careful judgment and in the consensus of the prewar designating committee, the finest known surviving work from the master who founded the Sōshū tradition. Its absence is felt in active scholarship. Comparative work on Masamune attribution still depends heavily on a handful of authenticated blades held in Japanese museums and shrine collections, and the loss of the Honjō from that comparative set leaves a small but consequential gap. The fact that the blade was lost not in a fire or a flood but at the seam between two bureaucracies, in peacetime, after the war it was thought to have survived, gives the case a particular sting.
Junji Honma’s response was to build the institution that has organized Japanese sword scholarship ever since. In 1948, on the advice of Colonel C. V. Cadwell of the Allied occupation, he and Sato Kanzan founded the Nihon Bijutsu Tōken Hozon Kyōkai, the NBTHK, the body that today examines, classifies, and documents nihontō for the Japanese state and for collectors abroad. The Honjō Masamune is the absent center of that work. Its possible recovery would resolve a specific historical question. Its current absence has shaped how an entire discipline organized itself.
Where the search stands now
No credible sighting of the blade has surfaced since 1946. Periodic claims appear in collector communities, and Japanese cultural officials remain interested in any verifiable lead. The wider field of historical and archaeological mysteries includes a long list of objects whose disappearance can be reconstructed only up to a final administrative gap, and the Honjō Masamune sits high on that list. Anyone holding a Sōshū-style blade with no clear provenance, particularly one inherited from a relative who served in the early occupation, has reason to ask a competent appraiser for an opinion. The blade is unlikely to declare itself. It is signed, if at all, in the handwriting of a fourteenth-century smith whose mark is hard to recognize without a trained eye, and the Japanese authorities who could authenticate it would prefer the chance to try.
In short: a sword that survived seven hundred years of war, fire, and dynastic turnover went missing in the third week of January 1946, on the day a Tokyo police station handed it to a sergeant whose name no one has ever been able to confirm.
Frequently asked questions
Who made the Honjō Masamune?
Gorō Nyūdō Masamune, a swordsmith working in Kamakura between roughly 1288 and 1328, made the blade. He is conventionally regarded as the greatest figure in the Sōshū tradition.
Why is the blade called “Honjō”?
The general Honjō Shigenaga (1540–1614) acquired the sword after a battle in 1561, and it took his name from that moment forward.
When did the Tokugawa family acquire it?
It entered Tokugawa custody around the turn of the seventeenth century, when Tokugawa Ieyasu received it from the Toyotomi house. It remained in the family for roughly two and a half centuries.
What is its current legal status in Japan?
It was designated Kokuhō, National Treasure, on 27 May 1939 under Japan’s prewar 1929 cultural property law. Because that designation predates the 1950 Law for the Protection of Cultural Properties and the blade’s whereabouts have been unknown since 1946, it is not currently listed under the postwar system.
Was it really handed to a “Sgt. Coldy Bimore”?
A receipt at Mejiro police station, dated 18 January 1946, names a Sgt. Coldy Bimore of the Foreign Liquidations Commission. No serviceman by that name has ever been identified. The most plausible reconstruction reads it as a phonetic spelling of T/4 Cole D. B. Moore.
Is the sword most likely destroyed or held privately?
Both possibilities remain consistent with the evidence. Specialists are divided. Destruction is consistent with the bulk fate of confiscated swords in early 1946; private retention is consistent with the wider pattern of officers shipping blades home as souvenirs.
Could it still surface in the United States?
It could. The blade is unsigned in the easily readable sense and would not announce itself to an untrained owner. A descendant of an early occupation officer who inherited an unsigned Japanese sword has reason to seek a formal appraisal.
Why didn’t the Tokugawa family hide the sword?
Tokugawa Iemasa chose visible compliance with the SCAP directive, partly to model good behavior for other former noble families and partly because he had no reason to expect the receiving bureaucracy to lose a Kokuhō.
What other Masamune blades survive?
The NBTHK recognizes about eighty-one blades attributed to Masamune across multiple categories of designation, including nine Kokuhō. Notable surviving examples include the Fudō Masamune and the Hōchō Masamune, both held in Japanese collections.
Does the search for the blade continue today?
Yes, informally. Japanese cultural authorities, the NBTHK, and private researchers monitor leads, and the absence of the Honjō Masamune remains an open file in the institutional memory of Japanese sword scholarship.
Sources cited in this article
- Kotō Meizukushi Taizen, Edo-era reference, life dates of Masamune (c. 1264–1343).
- Nihon Bijutsu Tōken Hozon Kyōkai (NBTHK) authentication tally for Masamune-attributed blades.
- Honjō Masamune entry, Wikipedia and Tokyo Nihonto reference essay, provenance from Honjō Shigenaga to Tokugawa custodianship.
- Markus Sesko, biography of Honma “Kunzan” Junji, with details of his 1937 examination at Tokugawa Iemasa’s residence.
- Japanese Cultural Property records, Kokuhō designation 27 May 1939.
- SCAPIN 181, 24 September 1945, full text in U.S. occupation records.
- Tokyo Nihonto, History Collection, and contemporary press summaries of the December 1945 Mejiro surrender by Tokugawa Iemasa.
- Mejiro police receipt, 18 January 1946, naming “Sgt. Coldy Bimore” of the Foreign Liquidations Commission, AFWESPAC.
- Imperial War Museums, Akabane Swords blog by Claire Mead, on the rescue of art swords from bulk destruction.
