Ko-Bizen Tomonari TachiKo-Bizen Tomonari

periodLate Heian (987 - 1185 AD)
designationNBTHK Juyo Token
nakagoo-suriage, mumei
nagasa70.0 cm
sori2.4 cm
motohaba2.7 cm
sakihaba1.7 cm
kissaki2.4 cm
nakago nagasa20.6 cm
nakago sorinone

… the overall appearance of the blade is considered as being supreme in shape and structure. Albert Yamanaka (Honami Kozan), on Tomonari

The Japanese sword in all of its elegance is an invention of the latter part of the Heian period. Swords had been fabricated in various places in Japan before this, conspicuously in Yamato province where some of the oldest blades originate, but the names of the old smiths tend to be lost in time and become legends. In the middle Heian and earlier, work styles are various, with straight chokuto and experiments with double edged swords and partially curved blades all extant. Thanks to the Shoso-in repository in Nara, we are lucky to see many interesting preserved artifacts from the 8th century showing these various work styles and techniques in the swords nestled amongst the objects preserved in this collection. Of note, none bear signatures of the smiths.

Something happens though, around 987, when we see the emergence of three important names: Sanjo Munechika in Yamashiro, and Masatsune and Tomonari in Bizen. In this time period came the emergence of the curved, ridged tachi with simple tang, blunt spine and heat-hardened edge as the primary and dominant form of sword. This degree of radical change was never encountered again, as for one thousand years smiths experimented but were only ever able to make variations on this theme. In these experiments and with the stylistic change over the centuries, the kissaki would elongate and then subsequently shorten, the length would increase and then shorten dramatically and increase again. The curve would change its focal point, moving up and then back down the blade. Wide blades gave way to tapered blades which gave way to wide blades and then tapered again. But the basic form was never improved on, it was already nearly perfect.

The most successful school of the late Heian, by the number of works we have left to examine, is the Ko-Bizen school. There are somewhere between 500 and 800 that exist based on what I have read, but an accurate number is difficult to come by. Ko-Yamashiro blades are even more rare than Ko-Bizen and we know the makers of the Sanjo and Gojo schools of Kyoto only by a small handful of blades.

The founder of Ko-Bizen is noted in old books to be a smith named Sanenari, but there are no works of his extant. His son is Tomonari and we find his works today though they are rare. Because of this he is considered the founder of Ko-Bizen, which also makes him the founding smith of the Bizen tradition. In fact, around eight centuries later, in the 1860s, Yokoyama Sukekane was signing in Bizen province that he was the “58th Generation Tomonari“, hailing the direct lineage to the grandmaster.

Working around the same time frame is Masatsune, who is an equal in skill to Tomonari, but they each have their area of supremacy.

Tomonari, Masatsune, Nobufusa and Kanehira are representative swordsmiths of the Ko-Bizen school … Amongst them, Tomonari of the Eien Era demonstrates the most classic and dignified workmanship … Generally speaking, amongst Ko-Bizen smiths, Tomonari is the most skillful smith in making sugata and Masatsune in forging jigane. In every way, Tomonari and Masatsune are the best two smiths of the Ko-Bizen school. Dr. Honma Junji (Kunzan)

[Tomonari] shows the most dignified and classic workmanship amongst Ko-Bizen smiths … [he] is one of the two greatest Ko-Bizen smiths, along with Masatsune. Masatsune demonstrates more sophisticated and artificial workmanship and in comparison to Tomonari's unaffected and simple [natural] one. Tanobe Michihiro (Tanzan)

The work of these artists would stand as the foundation for all the Bizen masterwork that would come over the next millennium. We are dealing with a period of time which is very far back, and we have to recognize that these swords were tools of warfare. Because they we used, damaged, destroyed and modified over time, today we have only very limited works left to us with which to make judgments about time periods and generations. In the case of Tomonari, there may have been several generations. With Masatsune the Ko-Aoe smiths were also active in this period and from the work styles and signatures left behind, there seems to have been possibly several Masatsune in both schools working over some period in the Heian to early Kamakura period. It is a normal situation that the further back we look, the more difficult absolute statements become.

It is possible that the Ko-Bizen style continued to hold true while the Ko-Ichimonji group developed, and then forked off Fukuoka and Yoshioka Ichimonji groups, while the Ko-Bizen smiths continued to work up until the middle of the Kamakura period. This to me though seems as if General Motors were still making 1957 Cadillacs in 2014 beside the most modern Corvette models. So, I'm not sure I accept that particular theory, rather I think that the Kamakura works that recall Heian works are more likely misplaced in time or else no different behavior than today where we commission certain things done to emulate styles of the past. I don't think that commercially an antique style could survive side by side with products that keep pace with the changes in warfare and technology that would always be a factor in ongoing development of weapons.

There is some argument then about the end period of Ko-Bizen and what it signifies, and how this style would continue to exist past the early Kamakura revolution sponsored by the Goban Kaji. For this reason sometimes we can look up Ko-Bizen smiths and see work periods contemporary to the early Kamakura or Ichimonji schools which are supposed to descend from Ko-Bizen. In the case of a smith like Sadazane, he has been placed in Ko-Bizen, in Ko-Ichimonji and in Fukuoka Ichimonji groups. Each of them has a different constraint on the time period, which will move the sword around in time, or one may agree with some overlap in the groups, in which case the sword can be dated by its shape and the group it came from can be left to argument. My own feeling is that the shape and construction is primary in determining the age. Various experts usually argue about construction, and refer to “it was the style of the times“ as justification for say Niji Kunitoshi choji work changing to Rai Kunitoshi suguba work. Fujishiro mentions about this that the end of the Kamakura was “the age of suguba” and argues that you cannot make associations based on work style as a result. I agree mostly with this assessment, and I feel that these antique swords of ancient shape and construction are works of the Heian rather than allowing them up to the end of the Kamakura period. When you compare them side by side with things like the major Fukuoka Ichimonji and Awataguchi smiths of the early to middle Kamakura period you can see a great rise in sophistication of the presentation. This is thought to be as a result of the flowering and exchange of technology after Emperor Gotoba brought together the 24 greatest smiths in the land to teach him swordsmithing. These ancient works in style and construction I think rightfully come from before this event.

Regardless of this, mostly what we consider to be the most cherished Ko-Bizen work is that of the Heian period, and these are held in reverence. Kurokawa san told me once in Tokyo that the more you learn about swords, the more you appreciate older blades, and when you are done with your education you will be left with Ko-Bizen. I quote the following from an essay by Thomas Buttweiler, who was a student and collector of Japanese swords:

There are perhaps 500 Ko-Bizen swords left in existence today. About 200 of these have been awarded Juyo Token status or higher [ca. 1980]. The vast majority of even these recognized examples are in greatly deteriorated condition. Nearly all of these have been polished down to a point where they retain only a hint of their former elegance. In many cases, the Boshi is incomplete or missing altogether. Many of the remaining blades have been burned or re-tempered. Even so, the desirability of such blades remains undiminished. The words of one elderly Japanese connoisseur while examining a blade with all of the above faults, are classic. He held the blade at arms length for a long time and turned, smile and said, “But, it's Ko-Bizen.”

Hallmarks of the Ko-Bizen school include jifu utsuri, which appear as dark ovals throughout the ji, with chikei, and extremely good steel. The sugata tends to be less elegant but more powerful than their contemporaries in the Sanjo and Gojo Ko-Yamashiro schools. Tomonari in particular is noted for peerless levels of skill in making sugata and ranks first amongst Ko-Bizen smiths. Fujishiro states that he is Sai-jo saku as one would expect, and the Toko Taikan gives a rating of 3,500 man yen, which is the highest rating in the book. To put this in context, the supremely talented and most famous smith of them all, Soshu Masamune is ranked at 2,500 man yen. As one might expect given all of this, there are works of Tomonari at Kokuho, and Juyo Bijutsuhin levels. There would be even more than what we see when we count them, which amount to a little more than a handful, if more existed.

There is an example of the work of Tomonari that is Juyo Bijutsuhin in spite of the fact that the boshi has been polished off on the sword. This is quite remarkable as for newer swords the loss of their boshi would cause them to fail Hozon, and this sword is one step away from Kokuho. It tells us something about the importance of this blade and this smith that it would be accepted at such a high level in spite of this “fatal flaw.”

We see such lenience as well in the NBTHK Juyo designation. Heian period blades are allowed condition issues that younger blades are not allowed in order to achieve this prestigious rating. Finding one that is healthy and especially with boshi intact is wonderful. It's key always to keep in mind the age we are talking about. Because so many Japanese swords that are “only” a few centuries old are in pristine condition, it creates a false sense that these artifacts must all be in such condition, and it really does not hold true. As well, the older the blades are the more important simple preservation becomes. Every new owner for instance should not immediately respond to his purchase by thinking how good this sword would look in a new polish. If everyone takes this approach with old blades, within a couple of centuries they will be as thin as paper and destroyed. So we really must not let our desire for aesthetics overcome what is the primary goal of preservation of grand old works.

Juyo Token Ko-Bizen Tomonari Tachi

Juyo Token Ko-Bizen Tomonari Tachi

This is a sword attributed to Ko-Bizen Tomonari by the NBTHK, and confirmed by Tanobe Michihiro (former head researcher for the NBTHK) and Dr. Sato Kanzan (former director of the NBTHK). It is a tachi that has been shortened for use as a katana like the vast number of pre-Muromachi koto swords. In spite of this, it retains the koshi-zori that is associated with tachi and in fact Tanobe sensei indicates that it still has the sugata of an old tachi on his sayagaki.

The shirasaya bears a long sayagaki by Dr. Sato Kanzan. He made this sayagaki for Shigemoto Tomoe, who owned the sword and appears to have been a swordsman of some status. Of particular note, the sword was polished by Ono Kokei in 1967. He was a specialist in polishing Bizen swords and was a student of Honami Koson, and died in 1994. He attained the title of Nihon Ningen Kokuho, in 1975 which we call Living National Treasure. In Japan, this is the highest status any craftsman can hope to achieve in any field, and there have only been a small number of sword polishers to obtain it: Nagayama Kokan, Honami Nisshu, Ono Kokei, and Fujishiro Matsuo.

At the time Ono Kokei would have been the most skilled polisher of Bizen swords in Japan and had been working for the Tokyo National Museum since 1947. He is the polisher who worked on the ancient swords from the Shoso-in repository, restoring 148 of them. These are the most ancient Japanese swords in good condition that exist. Furthermore he was selected to polish several Kokuho and Juyo Bunkazai swords.

The polish on this sword is quite classical without venturing into garish anywhere, and is in keeping with the ancient status of the sword. It is not so often that the polisher is documented on a blade, and because of this reference this becomes valuable information about his work. Since work of polishers tends to be transient and undocumented, it is even more important to preserve this blade in it current state, though some scratches have appeared on the sword since 1967.

The NBTHK first began ranking Juyo swords in 1958, and did only small groups of swords to start out with. For instance, there are only 23 swords in the first Juyo session. Contrast this with Juyo session 26 in the mid 1970s where there are 364 items. This sword passed in the 6th Juyo session which had 76 items go through. Probably the total number of swords passed in the first six sessions is less than the entire 26th session, which I believe shows very stringent criteria and careful consideration. The kinds of swords accepted in the early sessions tended to be signed masterworks of top ranked Shinto smiths, as well as grandmaster koto smiths (Sadamune, Shizu, Norifusa, Masatsune, and various Ichimonji, etc.) It is worthwhile to point out that at this point in time there were no Tokubetsu Juyo Token, as this level was not created until 1972. So in 1961, the criteria for Juyo Token meant that a blade had to be accepted at the very top level, and competition was very high since the pool of available swords to choose from was near its maximum. For these reasons, early Juyo Token like this are held in high regard and many of them have since gone on to pass Tokubetsu Juyo. In recent years the NBTHK has increased the threshold for passing Juyo again as only 93 blades were accepted in Juyo session 58 for example.

Dr. Honma asserted that the names of Tomonari and Masatsune have been handed down through the Heian into the Kamakura period, and Fujishiro also defers on the topic of date, leaving it open to a wide period beginning in 987 AD and ending in 1235 AD. The NBTHK has left the time period of Tomonari works a slightly open question as they did in the setsumei of this sword. The reason being that there are two dated works from 1235 and 1238 which appear with a Tomonari signature. These works seem to be of different age than the earlier Heian Tomonari as they have less elegant sugata and features of the Kamakura period. Of these two blades, Tanobe sensei writes that the possible explanations are that this is the legitimate time period for Tomonari, or it could be a descendant, or even:

… a smith who used the smith name, longing for him [Tomonari] after his age [had passed].

Dr. Honma does not think that these signed blades are by the same Tomonari that made the old works, as he writes of the 1235 dated blade:

… there is no doubt that it is much later work than the Otaru-maru Tomonari of the Imperial sword collection and a Tomonari tachi owned by the Yamamoto family.

These two dated blades have not passed through NBTHK Juyo Token, so without an assessment generally experts provide a date range for Tomonari. Christie's for instance stated 10th to 11th century in an auction of a Tokubetsu Juyo Tomonari, and in the case of this sword the setsumei provides only the statement that it's “not later than early Kamakura.” It's possible to refine the dating of the individual blades though by examining the sugata, looking for the hallmarks of Heian Bizen blades (ko-kissaki, fumbari, slender sugata, deep koshi-zori, elegant ko-midare hamon, jifu utsuri).

In spite of the difficulty of placing the origin of Tomonari and Masatsune and any subsequent followers from the end of the Heian and the beginning of the Kamakura, what is consistent in the views of experts is that the work of Tomonari is the most dignified, most classic, and the finest grade of skill of the Ko-Bizen smiths. A sword simply cannot be attributed to him without all of these components aligned.

I find this sword to be a representative example of the late Heian period, and it shows all of the traits one would desire in the work of Tomonari short of being signed and ubu. It is of classical sugata, with ko-kissaki and koshi-zori in keeping with Heian period blades. There are jifu utsuri, and elegant fumbari which also belong to the Heian period work of Tomonari. The boshi features nijuba which is another kantei point of this smith. The kitae is skilled but shows the rustic and natural construction that is associated with this smith. The truest beauty is in the hamon which as I wrote, shows that the high water mark for artistry was met very early by the the best Ko-Bizen smiths. Matching work of this tastefulness, and skill, is only possible for the greatest smiths of the Kamakura period, and in the minds of many collectors and judges, it has never been exceeded. The Heian period Kokuho Tomonari in the Tokyo National Museum has the same sugata and is described in the same way: “[it] shows a refined antique shape: a slim blade with high koshi-zori, funbari, and ko-kissaki […] the hamon features ko-midareba with little difference in height, ashi and yo.”

Albert Yamanaka describes the work of Tomonari and it seems almost as if he had this sword in hand:

The width of the YAKIBA is narrow in KO CHOJI MIDARE and there will be an abundance of KO NIE which turns into everything imaginable, also the NIE and the NIOI clusters around each other forming ASHI. INAZUMA. and KINSUJI are seen but they are not garish.

It's hard to clearly state the importance of a blade like this. It is not only a highly regarded early Juyo, but it stands among a very small and elite group attributed to Tomonari. This count is only eight for which the NBTHK has ventured the Tomonari attribution or confirmation at Juyo and higher. Of these eight, three are Tokubetsu Juyo and one of the Tokuju blades is Juyo Bunkazai as well. Two of those three Tokubetsu Juyo swords are signed, and the unsigned one is accompanied by very old Muromachi koshirae and a Nanbokucho period habaki. It was auctioned at Christie's in 1996 and achieved a staggering $401,045 USD price.

This Juyo sword featured in this listing was shown to me, like many I see in Japan, by quietly bringing it from the back room, and placing it on a table with the shirasaya in its sword bag with no words given. When I slid the sword out and saw its sophisticated beauty I immediately turned to the gentleman showing me the blade and said, “Ko-Bizen.”

He then removed the shirasaya from the bag and exposed the old sayagaki by Dr. Honma revealing it to be a work of Tomonari. This is a moment of real delight, not so much for the moment of making an accurate judgment but more for the pleasure of having a Ko-Bizen blade in hand of this degree of health. To have it attributed to Tomonari was beyond surprise. Just the chance to be near one or see one or hold one, let alone to be able to own one is wonderful. When I examined this blade, thoughts of flaws were far past my mind. I saw only sparking ko-nie like stars in the sky, and breathtakingly beautiful work in the hamon that I could only compare to the finest work of Masamune. This was really the only thought on my mind, that it was remarkable again to see that the Ko-Bizen smiths had gotten to these places far before anyone else, and that whatever existed that was great about swords in the centuries after was only some kind of reflection of something that came before. There are many interesting observations to be made in this sword, there are uchinoke and nijuba which are also features of Sanjo Munechika for instance, and shows that the oldest Yamashiro and Bizen works were not yet very separated in terms of style. As well, the lower part of the original tachi-omote of the nakago has not been refinished.

This area of the nakago is important as it confirms the old age of this sword. Since this sword has been shortened multiple times, this side would originally have had the signature and was not refinished during shortening because of this. So we can examine the deep level of corrosion and consider the fact that the shinogi virtually vanishes in this untouched area of the nakago while it has been neatly maintained on the flip side. Sadly, the very last shortening of the blade probably is the one that took the signature off the end of the nakago. Regardless, the signs are there to testify to the age of the blade.

The habaki is solid gold, but it looks to be in the 18 karat range (75% gold, the balance copper and silver). The sayagaki also indicates that this sword came with golden tachi koshirae. I was given the option to purchase the koshirae, but they seem to be contemporary with the habaki and were likely made in the 1950s or 1960s for this sword and the value I believed had more to do with the amount of gold involved than the historical or artistic importance. I felt then that they were not part of the historical status of the blade, but flashy items made to order for one of the modern owners. So I did not pursue them based on this.

It wasn't until researching this article that I found an article written in the Token Bijutsu about a signed Tomonari that is Juyo Bijutsuhin and was donated to the NBTHK. About this Jubi piece, Ishii Akira wrote:

Among Tomonari's signed tachi, this is the longest and has a very powerful feeling. It is more than 3 shaku long, and the jihada is a consistent itame hada from the moto to saki. Masamune, who established the Soshu Den school, is supposed to have admired this sword, and particularly its very natural ko-midare hamon and the nioi-guchi. The entire hamon, including the ha-saki, has fine thick ha-nie, also a controlled but varying thickness of the kinsuji, niesuji, and frequent sunagashi. The hamon is similar to those of Ko-hoki swords, which have a wild feeling or presence and an interesting hamon. Among Tomonari’s swords, this was made not later than the Heian era, and has a dynamic shape and at the same time, a very elegant look, and we could say that this is one of his best works.

It was a surprise to me to read this, as it echoed and confirmed my own immediate feelings on viewing this Juyo blade with its same ko-midare hamon decorated with ko-nie. I think if you look at all of the photos in the photos below, you should do so and keep these words in mind while you look at the photos. Think of the Soshu masters centuries after Tomonari looking at the work of the Ko-Bizen smiths, admiring it and trying to bring it back to life in their works. If you can do this, you can understand where Soshu comes from and when you study a blade like this, you will be able to get into the soul of Soshu as well as Bizen.

At almost a thousand years old, this ancient sword represents a very rare opportunity for a collector to have something very important… beyond words important. I take some risk by stressing this so much, but I am reaching for clarity.

This blade is a dignified crown jewel by the first smith among Bizen smiths, a man at the root of the longest and most renowned tradition of sword making. It has to be understood that this is more than just an antique, it is a relic from the beginning time of the curved sword and a representative work of Ko-Bizen.

It's value and importance goes beyond the beauty it still possesses. It is for someone who can understand what it represents, or who wants to learn from such an item over the span of years. The owner has to understand that they are taking a place in history as one of its guardians and insure it can be handed off to the next generation to properly preserve going forward. They need to care about who handles it, and about who receives it when their time is past. There are so few like this, so it is very important that the next owner be able to embrace this high degree of responsibility. As such, this is a sword for a only the most sophisticated collectors. I too will not sell this sword to someone I am not absolutely confident can take the responsibility of ownership of it seriously, and in turn I hope they will do the same. To say it another way, it is a situation where you don't simply sell a sword like this, rather it is something more akin to giving it up to adoption by another.

Ko-Bizen Tomonari Tachi Oshigata

Juyo Token Tachi

Appointed on the 25th of February, 1961

Katana, Mumei, Den Bizen Tomonari

Shinogi-zukuri, iori-mune, slender mihaba, blade keeps (despite the suriage) a deep koshi-zori, compact ko-kissaki.


Rather standing-out itame-nagare with ji-nie.


Ko-midare with chōji-ashi with plentiful of ko-nie which tends altogether to a shallow notare, in addition sunagashi and frequent kinsuji, the yakiba is a bit narrower before the yokote.


Appears as nijūba.


ō-suriage, kirijiri, kiri-yasurime, three mekugi-ana, mumei.


Here we have a slender Ko-Bizen ō-suriage mumei tachi which dates not later than the first days of the Kamakura period and which can be attributed to Tomonari. The blade has lost some substance along the monouchi but otherwise nothing of its beauty.


This sword bears on its shirasaya two long and beautiful sayagaki by Dr. Sato Kanzan, former director of the NBTHK, and Tanobe Michihiro sensei, former head research judge. Both confirm the judgment to Tomonari. Tanobe sensei made this sayagaki at my request very recently, and completely filled the available space with commentary (which I view very positively). At this time, he told me it was worthy of submission to Tokubetsu Juyo shinsa. Please note the changes in color on the shirasaya are because it is an old shirasaya that needed to have its surface cleaned in order for the sayagaki to be laid down. The wood has not yet re-patinated due to the recent sayagaki. It will naturally darken in the cleaned areas with exposure to light and air and will have a uniform patina once again.

As a side note, please look at the shape of the shirasaya. There was a game played by kantei masters in the Edo period where they attempted to guess your sword while it was still being worn. When you look at this shirasaya you see the primary clue about how this could turn out well for the guesser who knows his sugata well. And of course, you wouldn't lose much face for guessing a sword wrong if you didn't ever look at it.

Ko-Bizen Tomonari Tachi Kanzan

Kanzan Sensei Sayagaki

  1. 備前國友成
    Bizen Kuni Tomonari
  2. 但大磨上無銘也
    Tadashi ō-suriage mumei nari.
    The blade is greatly shortened, and unsigned.
  3. 刃長貮尺参寸壱分
    Hachō 2 shaku 3 sun 1 bu
    It is 2.31 shaku long.
  4. 金無垢糸巻太刀拵付
    Kinmuku itomaki-tachi-koshirae tsuke
    And accompanied by itomaki-tachi-koshirae with golden fittings.
  5. 昭和卅二丁酉歳初夏日
    Shōwa sanjūni hinoto-toridoshi shoka no hi
    On a day in early summer 1967, year of the rooster.
  6. 應需重元剣客
    ōju Shigemoto kenkaku
    On request of the swordsman Shigemoto
  7. 寒山誌
    Kanzan shirusu
    Written by Kanzan.
  8. 昭和卅二年初夏小野光敬研之了
    Shōwa sanjūni-nen shoka Ono Kōkei togi no ryō
    Polish by Ono Kōkei, finished in early summer 1967.

Ko-Bizen Tomonari Tachi Tanzan

Tanobe Sensei Sayagaki

  1. 古典的ナ太刀姿ヲ呈シ精妙ナ鍛錬ニ地斑映ガ現レ小沸出来ノ巧マタ小乱ヲ焼申候総体ニ古様サヤ優雄ナ品格ヲ備ヘテ深イ味ワイヲ醸成セリ
    Koten-teki na tachi-sugata o teishi seimyō na tanren ni jifu-utsuri ga araware ko-nie-deki no takumata ko-midare wo yaki moshi-sōrō sōtai ni koyō saya yūo na hinkaku o sonaete fukai ajiwai jōsei seri.
    This blade shows a classic tachi-sugata, a fine forging, a jifu-utsuri and a skilfully tempered ko-midare in ko-nie-deki.
  2. 古備前友成ノ古傅ハ尊重スベキ者而珍重然ルベキ哉
    Ko-Bizen Tomonari no koden wa sonchō subeki mono shikamo chinchō shikarubeki kana
    Ko-Bizen Tomonari´s classic style and workmanship are well preserved with this blade, and so we are facing here an esteemed and rare item which must be preserved.
  3. 第六回重要刀剣指定品ナリテ
    Dai rokkai jūyō-tōken shiteihin narite.
    It was designated as jūyō in the course of the sixth jūyō-shinsa.
  4. 刃長弐尺参寸一分有之
    hachō ni-shaku san-sun ichibu aru kore.
    Blade length 70.0 cm.
  5. 惟時甲午端月探山邉道追而識
    kore toki kanoto-uma tangetsu Tanzan Hendō tsui ni shirushite + kaō.
    Written by Tanzan Hendō (pseudonym of Tanobe Michihiro) in the first month of the year of the horse of this era (2014) + kaō.