Aoe KatanaAoe

periodNanbokucho (ca. 1356)
designationNBTHK Tokubetsu Hozon Token Katana
nagasa72.1 cm
sori1.73 cm
motohaba3.3 cm
sakihaba2.97 cm
kissaki7.0 cm
kiritsuke-meiくさの徒ゆ · 谷久兵衛所持之
Kusanotsuyu · Tani Kyūbei kore-o-shoji
Dew on the Grass · A possession of Tani Kyūbei
nakago nagasa18.9 cm
nakago sorislight
price -sold-

Bitchu and Bizen provinces were in western central Japan. They shared a border, and the three rivers Yoshii, Asahi and Takahashi run down from the mountains in this area, depositing high grade iron sand on their banks. Going east to west, distributed on these rivers in the Kamakura period would be the Ko-Yoshii and Ko-Osafune schools (on the Yoshii), the Ko-Ichimonji, Fukuoka Ichimonji and Yoshioka Ichimonji (on the Asahi), and the Katayama Ichimonji and Ko-Aoe schools on the Takahashi.

The Aoe smiths are said to take their name from a subdivision of the of the Fukuyama village, in Mizu of Bizen province. From here they transplanted to Bitchu province but preserved the name of their origin. The Aoe name is still seen in this area today, between the Asahi and Takahashi rivers. Yasutsugu is said to be the founder of Aoe from around 1120 AD, but his work isn't seen anymore.

Now, the actual distances involved here are quite small. Travelling 35 kilometers (20 miles) in a straight line you would cross over this entire territory of these three rivers from Osafune to Aoe and all the smiths in between. This small area was the major pulsing factory that over 500 years produced so many great works that they account for approximately 40% of all the existing Juyo Token today. The difference between Bizen origin and Bitchu origin is basically which side of the Asahi river you live on, and leads us to understand more clearly the close relationship between these smiths and schools. Though they are a stone's throw away, the difference in locality did produce some marked differences in workmanship.

Detail of Tokubetsu Hozon Aoe KatanaDetail of Tokubetsu Hozon Aoe Katana

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 as a style is often thought to bridge a gap between the choji developments of Bizen and the suguba and refined jigane styles of Awataguchi and Rai in Yamashiro. 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, while the Chu-Aoe works brought the art of steel to its highest level in Bitchu.

Detail of Tokubetsu Hozon Aoe Katana

Competing nomenclature: Aoe, Chu-Aoe or Sue-Aoe

The smiths of the Ko-Aoe group gave way to those we just call Aoe at the end of the Kamakura period. There are different sets of names used by different authors and schools of thought. The first divides Aoe into Ko-Aoe (old Aoe) up until the Kamakura period, then calls these smiths Chu-Aoe (middle Aoe) up until the Nanbokucho period, then calls the last group Sue-Aoe (end Aoe) until they extinguish some time in the Muromachi period.

The second set of nomenclature only uses Ko-Aoe and includes in this group smiths working up until the late Kamakura period, then uses Chu-Aoe to cover the smiths working until Aoe fades away. Sometimes Sue-Aoe is used for specific Muromachi period finds in this case.

The third set of nomenclature would be to just use Ko-Aoe, and Aoe for the rest. In this case the NBTHK would attribute a blade to Aoe school, and in this imply that it is a blade from the Kamakura-Nanbokucho border period up until the Muromachi period. If they mean older they will specifically call it Ko-Aoe then, which will place it into the Kamakura period. We like to think of these period divisions as very sharp borders but it's not the case. Everyone did not suddenly wake up one day and say well, it's 1334, we all need to change our styles. So in this case Aoe can also be thought of to be a bit of a broader umbrella which will cover some time going into the end decades of the Kamakura period where the styles were beginning to evolve into the Nanbokucho style.

This is important to recognize because any particular smith may at times be referred to as Aoe, Sue-Aoe or Chu-Aoe depending on which system the author is using, but they will all be saying the same thing.

During the Nanbokucho period 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. They furthermore preserved the choji hamon in the form of saka-choji (slanting choji) when all of the other Bizen schools saw it fade away and they resisted the Soshu influence which took over in Osafune after the Ichimonji schools fell into obscurity.

Detail of Tokubetsu Hozon Aoe Katana

Special Features

These features are those that were specific or best made by the smiths of Aoe:

  1. chirimen-hada 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 (Tanobe sensei points out however that the true secret to doing this has been lost).
  2. sumi-hada 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.
  3. dan-utsuri 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 is overlaid with suji-utsuri which is one to three levels of horizontal utsuri which parallels the cutting edge the way the sky glows when the sun is setting. When you rotate such a blade through the light you will see many different effects in the ji as a result of all of this subtle utsuri work. The Aoe smiths may have 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 utsuri in their work.
  4. namazu-hada it 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.
  5. katana-mei the 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.
Detail of Tokubetsu Hozon Aoe Katana

About the reasons for katana mei, we don't know for sure as no records were handed down. The Token Bijutsu relates a theory:

[...] 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. Token Bijutsu

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.

At the end of the Kamakura period 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 also changed 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.

As we proceed through 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 (and shared with the Katayama Ichimonji smiths where it may have originated). Some of the works in the Nanbokucho period 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 at this time due to shortening, 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.

While these changes were going on, the Aoe jihada also 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. We see katana mei very rarely in the Nanbokucho as this tradition was mostly dropped. 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.

Detail of Tokubetsu Hozon Aoe Katana

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 grand-masters 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.

Detail of Tokubetsu Hozon Aoe Katana
Tokubetsu Hozon Aoe KatanaAoe Katana Origami

Tokubetsu Hozon Aoe Katana

This blade bears a very obviously masculine shape of the Enbun era in the Nanbokucho jidai. The o-kissaki measures 7.0 cm, and the mihaba starts at 3.3 cm and goes to just about 3.0 at the kissaki. This kind of powerful shape with very little taper is the archetype sugata of the middle Nanbokucho o-dachi which were almost all shortened to easier to use lengths in the Muromachi period when fighting styles changed.

Most Aoe school blades feature variations on suguba with slanted ashi but a handful of them are done in saka-choji. In this case the hamon is based on suguba with large amounts of saka-choji, yo and ko-ashi throughout, and the hamon rises through the monouchi to make an ichimai (full tempered) boshi. This kind of boshi is usually strongly associated with Go Yoshihiro but it seems to go back to some Ko-Hoki works.

Since Aoe school work is rather uniform in skill and style it is hard to pinpoint individual smiths and so school attributions are common. This one though with this style of hamon with choji based in suguba and all of the small activities is on the unusual side. While most Aoe are quiet in construction some of them feature slanting choji and a lot of activity.

There are some small condition issues in the ji, however this is more than made up for by the powerful shape and the historical association of this blade.

This blade bears a go (a name for the blade) which is inlaid in silver (ginzogan), and so it is named Kusanotsuyu. This translates as Dew on the Grass. This kind of name has two references on a blade like this. Dew slides off of blades of grass so it is a compound that is found in the names of blades that are known to have great cutting ability.

Japanese makes for good puns (i.e. words with double meanings) and when we look at nicknames we need to look for second meanings. In the case of this blade the saka-ashi can be thought of as the shapes of grass blowing in the wind and the large number of yo present appear as drops of dew.

Sasanoyuki (笹雪・篠雪): Literally snow on a bamboo leaf, this term alludes to no force needed to cut with such a blade, just like snow slips from a bamboo leaf without further ado when it is too heavy. A similar nickname is Michishiba no tsuyu (道芝の露). It alludes to the dew (tsuyu, 道露) on roadside grass (michishiba, 道芝) which also slips from the leaves without any further ado. This rather uncommon name was used for a blade belonging to Kimura Shigenari (木村重成, 1593-1615) who fought an all-out battle at the Siege of Ōsaka but was caught and beheaded. The same allusion is used by the nickname Take no ha no arare (竹葉霰・竹の葉のあられ), lit. hail slipping from bamboo leaves.Markus Sesko, Tameshigiri

The other side of the nakago bears the name of the owner: Tani Kyubei. The Tani family were the originators of the practice of testing swords for sharpness. The well known Yamada family of sword testers descends from the Tani.

The situation is different in the case of Tani Taizen who is thus regarded as the true ancestor of systematic sword testing. He was born in Kyōroku two (享禄, 1529), the son of the Mino province bushi Fukuda Rokubei Masayuki (福田六兵衛正之), but was adopted in his young years by his uncle Tanino Tarōzaemon Tsunamori (谷野太郎左衛門綱衛) who was a retainer of the Rokkaku family (六角) in Ōmi province where he was eventually raised. His first name was Moriyoshi (衛好) and his youth name Kotarō (小太郎, also read as Shōtarō). The name Tani Taizen refers to the short form of Tanino and his ranking Taizan no Suke (大膳亮) and Taizen Daibu (大膳大夫). As a young adult he returned to his home province of Mino where he became a retainer of the local Saitō warlods, first the ruthless Saitō Dōsan (斎藤道三, 1494-1556) and later Dōsan´s son and grandson Yoshitatsu (斎藤義龍, 1527-1561) and Tatsuoki (斎藤龍興, 1548-1573) respectively.

After the downfall of the Saitō clan, he came into the service of Oda Nobunaga and gained military merits in the fifth month of Tenshō four (天正, 1576) in one of the battles of Nobunaga´s campaigns against the network of fortifications, temples, and communities belonging to the religious Ikkō (一向) faction. This earned him a letter of acknowledgement from Nobunaga, reportedly for taking and presenting five heads. After that, Nobunaga ordered him to join the forces of Hideyoshi to assist him in his subjugation of the Mōri clan (毛利). In Tenshō six (1578), he was given Hirata Castle (平田城) in Harima province which was connected to lands with an annual income of 6,000 koku. Hideyoshi was conquering Harima province at that time and Tani Taizen fought well for his new commander, but he died on the tenth day of the ninth month that very same year, i.e. Tenshō six, in a battle related to Hideyoshi´s siege of Miki Castle (三木城). He was fifty years old at the time. And it is reported in the late-Edo period Kansei-chōshū-shokafu (寛政重修諸家譜) that Hideyoshi had a pine planted on the grave of his loyal retainer Taizen. Markus Sesko, Tameshigiri

Tani Taizen proved his worth on the battlefield for Nobunaga and as mentioned above, personally killed five warriors in one battle for which Nobunaga rewarded him for outstanding performance in the field. He is said to have been out falconing one day and came onto a dead body in a rice field. He chose to use that opportunity to test how well his sword of the time functioned, and from how he positioned the body on the slope in the rice field to cut it became the standard for making the dotan (earth mound) that was used in later periods during official cutting tests.

Tani Moritomo
Tani Moritomo

Through later generations the Tani family would become daimyo, with Tani Moritomo earning the title of Lord of Dewa province while controlling the Yamanaga fief. He had followed Toyotomi Hideyoshi to Korea and fought so well that Hideyoshi granted him a Rai Kunimitsu katana and furthermore as part of his will gave him the wakizashi called the Tsurigakiri but it is not clear who made this sword and it may be conflated somehow with the Tsuriganekiri Rai Kuniyuki. In later years Moritomo allied himself with Tokugawa Ieyasu, a smart decision which is what ended up in his granted status of daimyo.

Tani Moriharu (谷衛治) is the son of Morinari, the first son of Moritomo. He had the names Kyubei (久兵衛) and Magoichiro (孫一郎). Kyubei had fought at Osaka with his father and under his grandfather's banner on the Tokugawa side. His father Morinari died early and did not succeed as daimyo, where Kyubei's uncle Morimasa ended up taking over from Moritomo. Morimasa and Kyubei seem to have been about the same age as Morimasa was born in 1598 and would have been 17 years old at the time Kyubei was fighting at Osaka in 1615. Some kind of politics ensued during this timeframe which had Kyubei end up leaving the Yamanaga fief and becoming a retainer in the powerful Matsudaira family, under Aki no Kami Mitsuakira. The Matsudaira of course are the greater clan from which the Tokugawa emerged, which indicates to me at least that his exile from Yamanaga had more to do with creating some distance from his uncle and not disturbing the power structure or inheritance that would normally have flowed to him through his father.

Kyubei's new sponsor was the young Aki no Kami Mitsuakira who became the daimyo of the Hiroshima domain, and was and the grandson of Tokugawa Ieyasu. The Asano family is key in the story of the 47 Ronin, as it was Mitsuakira's relative Asano Naganori of the Ako domain who was forced to commit suicide and thus impelled the long and complicated revenge enacted by the 47 Ronin. Due to his family's eminence in the field of sword testing, Kyubei was potentially responsible for this under the service of the Asano clan.

At some point, possibly associated with his service on the Tokugawa side at the defeat of the Toyotomi clan at Osaka, he was given or obtained this sword and named it Kusanotsuyu. Likely on his death and the inheritance of this sword this inscription was made to memorialize it as his weapon and so that its name was remembered. We know he was alive at the time of the siege of Osaka and he fought in this battle, so the time frame of his death was probably around 1650.

It's unusual to see silver inlay used for inscriptions on blades, and this seems to be a very old inscription by its style. Silver may have been used as a distinction from the gold used for attributions by the Honami clan, as this blade simply carries its name and the kiritsuke (memorial) inscription as Tani Kyubei's heirloom. The actual shortening of the blade was carried out beautifully and the blade retains all of its masculine characteristics, and it can be easily seen at a glance why a member of a prominent sword testing samurai family would choose this as his personal weapon.

This blade has a Tokubetsu Hozon paper to den Aoe as most of the Aoe blades that exist at this point in time from the Nanbokucho period are suguba without this large amount of ashi and yo and choji types of activities. It is in a state of old polish and would benefit from a new shiage (final stages of polish) which I can arrange for the new owner.

So many blades have been severed from their history in the sword world, so an artifact like this is a really nice collectible as it will forever retain its attachment at least as far back as the Momoyama period and the fateful battle at Osaka castle and a samurai who was present during this event which completed the unification of Japan.

For further information on the Tani family and the history of sword testing in Japan, I highly recommend Sesko's Tameshigiri which you can buy by clicking on this link and should be present in the library of the future owner of this sword. As well I have eight pages from the Kansei Chou Shokafu which is the history of the samurai families as compiled by the Tokugawa which is worth translating as a whole to understand better the history of the Tani family.