Aoe Sadatsugu KatanaAoe Sadatsugu

periodLate Kamakura Koto (ca. 1326)
designationNBTHK Juyo Token
nakagoo-suriage, kinzogan mei Sadatsugu (Hon'a Kao)
nagasa71.3 cm
sori2.4 cm
motohaba2.8 cm
sakihaba1.9 cm
kissaki2.9 cm
nakago nagasa17.7 cm
nakago sorinone

The pre-history of the Japanese sword is known from swords found in burial mounds, and the artifacts stored at the Shoso-in Repository. In the 700s during the end of the Nara period Emperor Shomu died and his wife the Empress donated some six hundred items in use during his life to the Todaiji temple in his memory. About 200 years later some other artifacts were relocated into this repository and the items were carefully preserved until the modern day where there are maybe 9,000 artifacts contained therein. Of the swords there, we don't know much about the makers and it's thought that some come from Korea and China. We see various types of shapes and experiments with tachi and tanto. All of this predates the modern; sword that we are familiar with that comes from around 1000 AD. They are generally felt to be related to the Yamato tradition and swords from Kyushu in the line that predates Samonji maintained much of this antique style. Amongst these swords, suguba hamon is common and thus is felt to be part of a great continuity from the earliest times until modern day. That is, though other styles of hamon have come and gone, there has always been and will always be elegant suguba.

Around 1,000 AD, Sanjo Munechika comes onto the scene in Kyoto and introduces the world to the shinogi-zukuri tachi and this new technology rapidly replaces all of the varieties and experiments of the past. With the rise of the Sanjo school he founded and its offshoot Gojo school, there are the smiths of Ko-Bizen and Ko-Aoe in nearby Bitchu province working around the same time in what we consider the late Heian period. Together these groups represent the forefront of swordmaking. The name Masatsune is famous in both Ko-Bizen and Ko-Aoe and today we have examples of many smith's work, but usually very few in number, but showing extremely high levels of skill each time. It then becomes difficult to categorize any unsigned Ko-Bizen or Ko-Aoe work to an individual smith but the styles of the works allow us to assign these to either group.

Aoe is said to originate in a subdivision of the same name of the Fukuyama village, in Mizu of Bizen. From here they transplanted to Bitchu province but preserved the name of their origin. Yasutsugu is said to be the founder from around 1120 AD, but his work isn't seen anymore.

The convention of the Honami was to maintain five traditions during the koto period: Yamashiro, Soshu, Yamato, Bizen and Mino. The reality of this is that it is a simplification meant to try to subdivide an unwieldy number of regional traditions based on local materials and techniques. For example, the Kyushu smiths which predate Samonji are not easily classified. We tend to throw them in with Yamato because the workmanship is a bit antique and unsophisticated seeming but this is not a fair distinction. Kyushu style is Kyushu style, but that does not really assist us in trying to take a bird's eye view and discuss nihonto in non-specific terms. So in this classification system some lines are blurred and schools can be related by reason of being more alike than dissimilar while other schools may share bloodlines so will be classified in the same tradition. Bizen and Bitchu styles, the latter of which contains Aoe, have intermingled and though they are distinct, Aoe is associated with Ichimonji, Osafune, etc. under this one big tent of Bizen Tradition works. As a result, for western collectors, it can pass by somewhat in stealth mode under the shadow of the name of its neighboring province. Dr. Honma however sorts them out as standing at a peer level with Bizen, Yamato, and Yamashiro in the Kamakura and earlier times rather than under the umbrella of Bizen.

Aoe is often thought to bridge a gap between Bizen style which developed suguba first into a ko-midare (small patterned irregular shapes) and then deeply into choji midare as made famous by the Ichimonji groups and the elegant suguba which was continuously maintained in Yamashiro by Awataguchi and Rai which would follow Gojo and Sanjo. In this they stayed true to a difficult and traditional form of work.

It's only natural for [students] to think that [suguba hamon is the simplest hamon to produce technically], but in fact we must realize it is the most difficult type of hamon to create. It's just like drawing a perfectly straight line without any notches and disorder. Technical skill capable of producing suguha in such perfection must be evaluated most highly. Furthermore, the quality of nioiguchi determines the quality of suguha as a whole; if it is too tight the hamon will lack the refined air and if it is too loose it will turn out to be in-attractive. Midareba allows some minor blemishes while there is no room for any perceptive deception as far as suguha is concerned. The difficulty with producing a perfect suguha rests in this very point. [...] You would be totally amazed at how perfect the suguha on the ancient works including the treasures in the Shoso-in are. Dr. Honma Junji

The smiths of the Ko-Aoe group gave way to those we just call Aoe at the end of the Kamakura period. The Aoe smiths are sometimes called Chu-Aoe and some would say these are followed in the Muromachi period by Sue-Aoe but there is not much standardization in these terms. The smiths of Aoe seem to have maintained traditions while Bizen went off into experiments and began producing nioi-deki swords. Aoe maintained development in nie but we see Bizen features in their blades still, usually with utsuri but also we see several special features that are unique to this school that causes it to be distinct from the rest of the Bizen schools and exposes some of the line blurring required for the Honami five schools concept to be deployed.

sword picture

Sumi-hada embedded in fine itame and ji nie

What we see in Aoe are features called chirimen-hada which is a crinkled texture that reminds one of crepe silk. This hada is formed by embedding fine patterned itame within mokume patterns during forging and then coating it all with ji-nie. And, there is sumi-hada which are areas where the steel color changes, said to be dark but clear. Dr. Honma says that this is a softer type of steel and is one of the key things to look for in Aoe kantei. The third unique feature is in the utsuri, where the Aoi smiths were able to fabricate multiple layers of interesting ghostly patterns in the ji. The term utsuri means a reflection, and usually it is some kind of reflection in the hamon. The exact structure of utsuri is still open for debate, and not all utsuri is a simple reflection of the hamon but as we see in Aoe works it can be multi-layered and complex and exceedingly beautiful, making the works of this school very special when the utsuri is very good. The earliest utsuri began with areas called jifu which look like fingerprints, and then would extend to become midare or choji utsuri which appear to mirror the hamon (hence the name coming from the word for reflection). The smiths of Aoe were able to layer several different patterns of jifu and midare on top of each other to produce a three dimensional effect. This multi-layered utsuri which changes aspects as you rotate a blade through the light is called dan-utsuri. How exactly the Aoe school became the masters of utsuri is hard to know because we don't quite entirely know what utsuri is still. But the theories point to a combination of material and technique (which maybe sounds a bit obvious), but may indicate that they had access to a particular grade of iron sand in their locale that other schools did not. This exposed special properties when worked and from its basic discovery the Aoe smiths worked on enhancing and developing this feature in their work.

There is another term, namazu-hada which is not seen so much but is meant to describe areas of dark hada which appear to have no texture and this reminded the old sword judges of catfish skin that had no scales, from where it takes its name. There would be texture here but this still would have been forged so tightly that it became muji and then was mixed in with steel with less forging and embedded into it. One can theorize that this was ongoing experiments with making hybrid materials that better stood up to the wear and tear of everyday use.

Ko-Aoe works are also considered to be among the most elegant blades, with deep koshizori and ko-kissaki that connect them strongly to the early years of tachi making. Aoe smiths in the older periods tended to sign in two characters, and the character Tsugu (次) is commonly handed down through their lines going for centuries. During the Nanbokucho period many Aoe smiths began to sign on the opposite side of the blade to everyone else in Japan... this began earlier in the Heian period with one of the Yasutsugu group smiths and several other Aoe smiths signed on either side. What this means is now a subject for speculation only, but the best reason is given by one of Sato Kanzan's students in the Token Bijutsu.

[...] since the [signature] was to represent the maker's spirit and conscience as well as for preventing forgery, the act of inscribing in a non-conformist way had a meaning in itself.

That is to say, it was a way of saying we are different, and we are special, those of us making these swords in Aoe.

During this time we also see many examples of signature and date appearing on the same side, and this too is unusual to see (these are called kakikudashi-mei). Signatures changed during this period from two character signatures to full length signatures featuring the name of the province, similar to what happened in Bizen nearby (and also in Yamato as some of the rare Yamato signatures do list the province in them). For some reason this did not seem to spread to Yamashiro, though it is certainly seen in Soshu too.

In the Nanbokucho period the Aoe techniques split, where the traditional style based on suguba was continued and also a style based on Bizen choji midare but with slanted midareba was developed. Some of the works became quite massive and as a result most lost their signatures in the Edo period when they were cut down in size to wear as katana. Because of the lack of signatures available many swords made by the Nanbokucho Aoe smiths now only carry an attribution to the school. Confusion is made worse by the Aoe school consistently handing down names like Moritsugu and others through the years, and then having no date... making signatures appearing consistently though the era and work style changed. This makes it very hard to know which is which, just that through the workmanship's common denominators as described above they can be put to the same school and/or period.

During this time period Aoe jihada became more refined and beautiful with tight, jewel-like ko-itame becoming seen and the sori straightened out with large kissaki and massive shapes which is a common thread in Nanbokucho schools. Nie and ko-nie development was left behind in favor of nioi from neighboring Bizen as well. Sumi-hada increased and chirimen-hada decreased. Though these works were highly skilled and easily at the level of the main line Bizen smiths working in Osafune, Aoe work at the top levels seems to have suddenly come to an end at the beginning of the Muromachi period. This would conclude the majority of a 400 year span of work that reached the top levels of artistry.

Gotoba and the Kamakura Golden Age

While most collectors are intimately familiar with Ichimonji works due to their flamboyant and easily recognizable nature, the more subtle nature of Aoe work can sometimes slip below the radar.

Understanding the prominence and importance of Aoe begins with Emperor Gotoba, who selected smiths from the various swordmaking regions and brought them together to teach him sword craft. It is thought that this process of bringing the grandmasters of Japan together, and likely the competitive spirit that was thereby engaged, is one of the driving factors for the blossoming of the Kamakura period and its status as the golden era of the Japanese sword.

Gotoba's first group of teachers numbered twelve, one for each month. They were selected from Yamashiro, Bizen and Bitchu. Three of the first eight teachers were Aoe smiths: Sadatsugu Tsunetsugu, and Tsuguie. This also lets us know that Aoe were prosperous and held at the same level as the Awataguchi and Ichimonji smiths of their era which represent the pinnacle still of the Yamashiro and Bizen traditions. It's also important as it helps to date Aoe work, as there are no dates written down earlier than the middle to late Kamakura period.

Gotoba himself would go on to become an accomplished swordsmith, and signed his works with a Kiku (Imperial Chrysanthemum) and a diagonal Ichi mark. At least one of these still exists today.

Juyo Token Aoe Sadatsugu Katana

Juyo Token Aoe Sadatsugu Katana

This sword was appraised by Honami Kokyu (16th Honami master) in the Edo period, roughly around 1760, as the work of Ko-Aoe Sadatsugu. He is Sai-jo saku and is one of the teachers of Emperor Gotoba as listed above. He is noted as having made swords in suguba or ko-midare by Fujishiro and having made them in excellent form. The name of Sadatsugu was handed down through Aoe and is present up until the Nanbokucho period. In 1336 in particular there is Osumi Gonnosuke Sadatsugu working in Aoe who is Jo-jo saku and his work bridges the period between the end of the Kamakura and beginning of the Nanbokucho periods. He is also ranked ryo-wazamono for very effective cutting ability. There are Tokubetsu Juyo works by both but signatures are mostly gone at this point in time from what is left to us.

Ko-Aoe Sadatsugu was ranked in the Shinkan Hiden Sho as one of the top smiths of Bitchu style and gave a value of 15 kan which according to the NBTHK was one of the top rankings available in this old book. They qualify this attribution of Honami Koyu however and state that when the Honami made this attribution what they were trying to say was that this particular blade represents the very top class of Aoe work rather than as a direct attribution to Sadatsugu. This special attribution has been documented in the NBTHK publications as well.

Sadatsugu's line continued through the Kamakura on to the Nanbokucho period, and prospered as the most representative pedigree in the entire Aoe school. It should be noted that the unsigned Aoe examples which were attributed to Sadatsugu by the Honami are not necessarily typically exemplary of Sadatsugu's craftsmanship; rather the attribution was significant in terms of warranting the best representatives of the Aoe school's work. Such masterpieces attributed to Sadatsugu by the Honami include a katana named Meibutsu O-Aoe inscribed Sadatsugu Kore-a suriageru, Hon'a (kao) in gold inlay, and a katana named Meibutsu Ko-Aoe and gold-inlaid Sadatsugu. NBTHK English Token Bijutsu

The blade as well does possess the very deep sori and smallish kissaki of earlier classical and elegant construction from the Kamakura period rather than the straighter, massive and o-kissaki blades of the middle to late Nanbokucho.

For me this blade stands out in particular because of the complex multi-layered dan-utsuri (which is not visible in the straight on formal photos but must be seen in angled light) it exhibits, as well as the elegant form with small kissaki and tapering sugata. And then the extremely beautiful jigane... I fell in love with it as soon as I saw it as emblematic of grand old Koto workmanship. It came into my hands because it was brought into a dealer during one of my visits to Tokyo. The son of an elderly collector had brought it in for sale, due to the ill health of his father and I bought it.

The blade was accompanied by what was a really great find in my opinion, a Tokugawa family Edo castle duty koshirae. The Tokugawa had strict rules about what was possible to wear on formal duty, quoting from the NBTHK:

In the Edo period, strictly regulated daishō mountings were introduced which had to be worn when at official occasions. These special daishō-koshirae were called kamishimo-zashi (裃指, lit. “worn with the kamishimo”, the official dress of the samurai) or banzashi (番指, lit. “worn at official occasion” or “worn when on duty” in or around Edo Castle).

According to the Bakugi-sankō (幕儀参考) which describes bakufu-related uniforms and the like, such a kamoshimo-zashi or banzashi had to composed of gloss black-lacquer saya with a straight kojiri for the dai and a round kojiri for the shō. The tsuka had to be covered with white same and wrapped with a black cord in hishimaki. The kashira had to be of black-lacquered horn and the fuchi of polished or nanako-accentuated shakudō. The tsuba had to be of polished shakudō, i.e. they had to be so-called kenjō-tsuba (献上鐔), and the mitokoromono high-quality Gotō works. The only other decoration allowed for the fittings were gold iroe family crests. The sageo had to be black or purple if such a daishō was intended as gift. However, all other daishō worn by samurai were not regulated but we find various daishō interpretations which are based on this formal kamishimo-zashi/banzashi.

Aoe Sadatsugu Katana Koshirae

sword picture This katana mount fits the entire description to a letter though the purple from the gift sageo is seen in the tsuka ito. It is possible that this is a newer repair as fixing tsuka ito is permitted for passing Tokubetsu Hozon. Furthermore, the blade has a solid gold two piece habaki with Tokugawa mon engraved sukashi style. Koshirae usually have just a wooden habaki on the tsunagi but in this case some caring owner years ago when the shirasaya was made had a gold foil habaki made just for the tsunagi. The mitokoromono in this case are gold on shakudo, and unfortunately there is a little bit of damage from wear on the backs. The saya as well shows a long history of use, some chips and scratches are in it as well as some fingerprints and signs of old period damage repair. I think though that these are not so detracting but are signs that it has made it through from the Edo period authentically, and this was a mount that was worn and used and not made minty fresh a few years ago by restoration in a modern workshop.

The NBTHK gave the mounts themselves Tokubetsu Hozon papers which are not easy to acquire for kodogu, being about a half step to Juyo if we were talking about it in sword terms. Furthermore the mounts were included as a mention in the Juyo papers making it a Juyo set with the sword.

My feeling at the time was that this is the kind of thing that gets disassembled in Japan and the fittings will end up in a box and be replaced with low class items, that the habaki from the koshirae would be switched onto the sword and someone would sell the solid gold two piece habaki separately. By slicing the package up into components a thrifty dealer can find an enthusiastic and specific customer for each component and maximize his return. I felt that by intervening I could keep this set together and a rare daimyo or high level retainer package like this is something that should indeed be preserved.

This sword is made quite thick in niku (the cross section) and this is never apparent in a blade in photos. You first notice it when picking it up because the blade feels heavy instead of light, as is common for most koto due to polishing. And this is in spite of its elegant shape. There were some problems with the polish on this blade at the time and it was an agonizing decision to make about preservation and whether I should attempt to have the blade restored. I thought about it for months and left the blade in Japan while considering it, but lucked into an opportunity to have the sword polished by Saito Tsukasa san. He was one of the students of Kokan Nagayama (Living National Treasure) in the 1970s and won Toku-sho awards (top rank) at the the NBTHK sword polishing competition eight times making him Mukansa, above competition. He is considered to be one of the best polishers in Japan today. I felt he would treat the blade properly, restore its state with minimal impact to health so I gave the blade to him to take care of and the results are spectacularly beautiful.

There are some small flaws on the bottom of one side of the blade, but these are not problematic on a blade of this age and quality and is in keeping with most works of even Tokubetsu Juyo level.

So I am adding this sword today with a lot of pride. It's old mounts are intact from the 1700s and signify service at a very high level and are a great example of official wear for a high level retainer or daimyo at Edo castle. It is a rare example of kinzogan mei by Honami Kokyu, the 16th generation Honami master. The solid gold habaki and gold habaki for the koshirae show that this has been cherished for a very long time. And the attribution to Sadatsugu indicates that it is an example of the very best of the Aoe school. The opinion I got in Japan was, "I think, maybe Tokubetsu Juyo", so it may stand as a candidate for elevation, especially with the spectacular refresh by Saito Tsukasa san. There are 60 such works, about 6% of all Tokuju, for this school alone. There are a further 41 Juyo Bunkazai and four Kokuho, illustrating the high regard for Aoe.

sword picture After WWII Japan started a licensing scheme for owners of swords and in the first year of this (1951) the daimyo collections were for the most part put through licensing. This was done for two reasons, to set a precident for all sword owners and also to demonstrate that it wasn't a confiscation scheme. It is useful then to check blades that have been in Japan until the present to see if their license (torokusho) lines up with Showa 26 (1951) as it tends to confirm other evidence that a blade was in a daimyo collection. These licenses are surrendered when a blade is exported from Japan, but I took a picture of this one before it was surrendered and it is indeed Showa 26 as to be expected from the Tokugawa mounts. The license number and date is also recorded on the Juyo papers when a blade passes Juyo.

I submitted this blade to Tanobe sensei for sayagaki and he wrote so much that it extended to the back side. This happens only very rarely, as it is entirely possible to write something like, "The blade shows all the characteristics of the smith" and end the commentary there. In my experience he exerts his best efforts on blades he truly appreciates and what he put into this as well as his specific comments about its quality and excellence show his opinion well.

Aoe Sadatsugu Katana OshigataAoe Sadatsugu Katana Koshirae Tokuho

Juyo Token

Appointed on the 10th of November, 1995

Katana, kinzogan mei: Sadatsugu - Hon'a (kao) [Honami Kokyu]

with black roiro-lacquer saya uchigatana-koshirae


shinogi-zukuri, iori-mune, normal mihaba, thick kasane, relative deep sori, chū-kissaki


dense ko-itame with fine ji-nie, chikei, and an utsuri that appears as midare-utsuri in places and as dan-utsuri in places


chū-suguha mixed with ko-gunome, angular ko-gunome, some nie-hotsure along the habuchi, ko-ashi, yō, fine kinsuji, and sunagashi, the nioiguchi is tight, the blade is basically hardened in nioi-deki but shows ko-nie


notare-komi with a ko-maru-kaeri


on both sides a bōhi that runs with kaki-nagashi into the tang


ō-suriage, kirijiri, katte-sagari yasurime, one mekugi-ana, the sashi-omote side bears under the mekugi-ana and on the hira-ji of the tang the kinzōgan-mei “Sadatsugu,” and the ura side bears at the same location the kinzōgan-mei “Hon’a + kaō”


The smith Ko-Aoe Sadatsugu was well-known since he was listed in the Kanchi’in Bon Mei Zukushi as one of ex-emperor Gotoba’s goban-kaji. The Shinkan Hiden Shō states that he was one of the very best smiths when it comes to Bitchū-mono and gives his blades a monetary value of 15 kan, an amount that belongs to the highest values issued by this publication. So Sadatsugu was one of the top Ko-Aoe smiths but several successors using this name were active until the Nanbokuchō period. Because of this, there was the tendency to attribute Aoe blades that show a typical workmanship and an excellent deki to Sadatsugu.

This blade shows a dense ko-itame with a dan-utsuri and a hamon in chū-suguha with a tight nioiguchi and saka-ashi, what speaks for a typical deki of an Aoe work from the end of the Kamakura to the early Nanbokuchō period. And as indicated above, it was probably the outstanding deki of the blade that caused Hon’ami Mitsuhisa to issue a straightforward attribution to Sadatsugu via a kinzōgan-mei and not just to Aoe. The katana has a healthy sugata with plenty of niku and a fine and excellently forged jigane that reminds of Kyō-mono (i.e. Yamashiro swords) and a further plus is the abundance of hataraki (activities) in ji and ha. The blade comes with a black rōiro-laquer saya uchigatana-koshirae.

Aoe Sadatsugu Katana Sayagaki


This sword bears an extensive inscription (sayagak) by Tanobe Michihiro is the retired former head researcher of the Nippon Bijutsu Token Hozon Kyokai (NBTHK).

  1. 第四十一回重要刀剣指定品
    Dai yonjūikkai jūyō-tōken shiteihin
    Designated as jūyō-tōken at the 41st jūyō-shinsa
  2. 備中國青江貞次
    Bitchū no Kuni Aoe Sadatsugu
  3. 大磨上茎ニ本阿弥光久ニヨル同工極メノ金象嵌銘有之
    ō-suriage nakago ni Hon’ami Kōkyū/Mitsuhisa ni yoru dōkō kiwame no kinzōgan-mei aru kore.
    This blade has an ō-suriage nakago with a kinzōgan-mei appraisal by Hon’ami Kōkyū (also read Mitsuhisa) to Sadatsugu.
  4. 貞次ハ後鳥羽院番鍛冶ガ著名ナレド以後モ同名ハ継承サレ南北朝期ニ亘ッテミラル
    Sadatsugu wa Gotoba’in ban-kaji ga chōmei narudo igo mo dōmei wa keishō sare Nanbokuchō-ki ni watatte miraru.
    Sadatsugu is famous for being one of the goban-kaji of ex-emperor Gotoba but his name was used until Nanbokuchō times.
  5. 古本阿弥家デハ各時代ノ青江ト鑒シ特ニ代表的且出来秀抜ト認メタ者ニ貞次ト極メル習ハシガ知
    Ko-Hon’ami-ke de wa kaku-jidai no Aoe to kangami-shi toku ni daihyōteki katsu deki shūbatsu to mitometa mono ni Sadatsugu to kiwameru narawashi ga shiraru.
    In olden times, it was customary for the Hon’ami family to attribute the most representative and best Aoe blades to Sadatsugu, regardless of their actual production time.
  6. メル習ハシガ知ラル本刀ハ建武前後頃ノ同派ノ特色を明示スル優品也
    Hontō wa Kenmu zengo goro no dōha no tokushoku o meiji-suru yūhin nari.
    This blade shows the characteristic features of Aoe school works from around the Kenmu era (1334-1338) and is apart from that a great masterwork.
  7. 長弐尺参寸五分余
    Nagasa 2 shaku 3 sun 5 bu yo.
    Blade length 71.3 cm
  8. The obverse dated and signed by Tanzan Hendō (Tanobe Michihiro)