Ko-Osafune Kagemitsu TantoKo-Osafune Kagemitsu

periodLate Kamakura (ca. 1315)
designationNBTHK Tokubetsu Hozon Juyo Token 63 (passed for the owner)
nakagoubu, slight machi-okuri, 2 mekugiana
mei備州長船住景光 - Bishu Osafune ju Kagemitsu
nagasa27 cm
sorislight uchizori

The greatest of all schools is the Osafune school of Bizen province. It lasted for 350 years of continuous sword production, and even though the end of the koto period represents the limits of its endurance, there were indeed still smiths working and signing Osafune into the Shinto period making a span of over 500 years.

The province which had the most developed swordsmiths among the kaji of all the provinces was Bizen, and it is probably no exaggeration to say that one third of all the kotō masterpieces which we cast our eyes upon today were made by the Bizen swordsmiths. The ones who flourished most among these Bizen swordsmiths were the four generations of the Osafune families of Mitsutada, Nagamitsu, Kagemitsu and Kanemitsu. The first three generations right at the beginning are often referred to as Ko-Osafune or the old Osafune school smiths. Fujishiro Yoshio

Among the BIZEN MONO this [Osafune] school was the most prosperous, had the greatest number of eminent smiths and among these the most excellent were MITSUTADA, NAGAMITSU, SANENAGA, and KAGEMITSU.

As for the products of the above mentioned various smiths in the initial period of OSAFUNE, the sugata is good, the jitetsu is good, the technique for the hamon is good, and since there is nothing needing an apology in regard to all their points, from olden times they have been prized as swords worn by famous generals and brave warriors, and there are no small number of historical facts and oral traditions related to this. Nihonto Koza

The main line of Osafune goes as such:

  1. Mitsutada (founder)
  2. Nagamitsu
  3. Kagemitsu
  4. Kanemitsu (Masamune Juttetsu)

By the time when Kanemitsu peaked in skill all of the other schools in Japan were starting their major fade-out. At this point Soshu was diminishing with Akihiro being the final great Soshu smith, the Yamato schools were in retreat, and Yamashiro had its students of traditional Yamashiro mostly dispersed into other areas and Hasebe Kunishige moved back to Kyoto bringing the Soshu tradition with him. Nobukuni, the other major Yamashiro figure of this era is thought to have been a student of Sadamune and his output as well was highly influenced by Soshu and at times Hasebe and Nobukuni completely overlapped into Soshu style manufacture.

Mino at this time was under development by the students of Shizu Kaneuji, and even the work of Kanemitsu and Chogi (the two top smiths working at the end of the Nanbokucho period) were highly influenced by Soshu to the point that we call them Soden-Bizen smiths.

The main line of Osafune becomes fuzzy a little bit after Kanemitsu due to the number of talented students he had with none really standing out among the rest. These are Masamitsu, Yoshimitsu, Rin Tomomitsu and others. During this time both Chogi and Motoshige maintained branches in and around Osafune which were a little bit different from main line Osafune work, and Omiya and Kozori also existed and were in the area though they seem to have been making a somewhat lower end product than what came out of Kanemitsu's forge.

After Kanemitsu is gone, the Oei-Bizen smiths Morimitsu and Yasumitsu continued the Osafune line and were at their time the finest smiths in the country. Osafune would continue and produce many more excellent smiths such as Yosozaemon Sukesada and Gorozaemon Kiyomitsu among others, and would eventually fade away (though it would never truly disappear) at the end of the Muromachi period.

Ko-Osafune Kagemitsu

As for the Bizen school, Kagemitsu is to be considered the first major tanto maker, although Nagamitsu also is known to have made a few works.


Kagemitsu, needless to say, made all his blades in narrow shapes, tempering quiet edge patterns almost in plain straight lines. English Token Bijutsu

Kagemitsu is a keystone smith in the Bizen tradition. Of all tanto makers from Bizen, he is considered the best and most skilled. He worked during a time where there were other great tanto makers and he is usually grouped within the top four or top six of these all time: Awataguchi Yoshimitsu, Shintogo Kunimitsu, and Rai Kunitoshi are named, and sometimes Sa, Etchu Norishige, round it out. You can note the absence sometimes of Masamune and Sadamune. Though they made excellent tanto, they are not always considered in the top group of tanto makers. There is universal acclaim for his skill as can be seen below.

Osafune Kagemitsu is one of master tanto makers ranking with Awataguchi Yoshimitsu, Rai Kunitoshi and Shintogo Kunimitsu. There are many extant masterpieces of tanto by Kagemitsu although his father Nagamitsu left a few tanto. Tanobe Michihiro, Token Bijutsu

Student A: Who do you consider the best of all master tanto makers in the entire history of Nihonto?

Sato Kanzan: I believe the two foremost masters to be named first are Awataguchi Toshiro Yoshimitsu and Shintogo Kunimitsu, followed closely by others such as Rai Kunitoshi, Bizen Kagemitsu, Etchu Norishige and Samonji in Chikuzen. They all were undoubtedly the most skillful. English Token Bijutsu

Kagemitsu is the premier dagger smith in Bizen, ranking with great figures like Awataguchi Yoshimitsu, Rai Kunitoshi, [Shintogo] Kunimitsu, and Etchu Norishige. This dagger is unusual for the period in that it has a slight sori, but it shows a good shape. It is called Kenshin Kagemitsu, as it was the sashiryo (carried in the sash) of Uesugi Kenshin , and was long handed down in his family. It has itame with midare utsuri, kataochi gunome, a sound blade and surface. This is one of Kagemitsu's finest. Suzuki, Japanese Daggers

Rai Kunitoshi is well known as master smith of tanto as well as Awataguchi Yoshimitsu, Shintogo Kunimitsu and Osafune Kagemitsu. Rai Kunitoshi and Kagemitsu produced many tachi but it is very rare to see extant works of tachi by Yoshimitsu and Kunimitsu. Token Bijutsu

Kagemitsu along with such masters like Rai Kunitoshi, Samonji, Shintogo [Kunimitsu], [Awataguchi] Yoshimitsu, Norishige, Masamune and Sadamune is considered to be the master at making tanto [...] however there are relatively few of these remaining and the few that are remaining are all considered to be outstanding. Albert Yamanaka, Nihonto Newsletters

This line of the first four Osafune masters is probably the most prestigious line in the history of nihonto. Between these four smiths are 176 Juyo Bijutsuhin, Juyo Bunkazai and Kokuho swords. Together the first three smiths account for more than 10% of all Kokuho (National Treasure) swords (Kanemitsu has none). All of these are illegal to export from Japan. Kagemitsu on his own has passed 93 blades through Juyo of which 8 went on to pass Tokubetsu Juyo, and has a further 18 Juyo Bijutsuhin, 16 Juyo Bunkazai and 3 Kokuho.

To say he is an important smith is a vast understatement.

Kagemitsu's daggers are of two types: a Kataochi gunome (as seen here) and suguha. The fomer stresses nioi; in the latter blades with nie are common. Suzuki, Japanese Daggers

Kagemitsu forges one of the most beautiful jigane and jihada is fine and dense ko-itame hada with fine ji-nie. He tempers hamon based on squarish gunome, slanted ko-choji and kataochi-gunome then the pattern tends to be slanted on the whole too. His jigane is very clear and hamon very bright. Token Bijutsu

Meibutsu Kokuho Koryu Kagemitsu
Meibutsu Kokuho Koryu Kagemitsu

Though he is primarily known for his skill in making tanto, Kagemitsu was also a master of tachi manufacture and his masterpiece work is the Meibutsu Koryu Kagemitsu (the Little Dragon). This blade was owned by Emperor Meiji and is now property of the Nation of Japan, and can be seen in the Tokyo National Museum. It is of course Kokuho, a National Treasure, and very much deserves its rank.

Kagemitsu along with Sanenaga and Nagamitsu make a particular kind of boshi called the sansaku boshi. This has a notable bulge in the middle and is otherwise in suguba and is a key kantei point for their work. Kagemitsu and Sanenaga were responsible for much of the work of Nagamitsu, as today there are too many swords and masterpieces attributed to or signed by Nagamitsu to be accounted for by one smith. Osafune rose to such height of popularity and had so many master smiths working for it, that these groups would manufacture under the guidance of the head of the forge. In turn Kagemitsu took over and had such smiths as Kagemasa and Kanemitsu working directly for him, and probably Sanenaga and his student Chikakage (who also learned the sansaku boshi).

Kagemitsu has the title of Sahyoenojo which we know from the presence of one of the Juyo Bijutsuhin blades. This blade though it is very much polished down is an important reference piece for this fact and I was lucky enough to be able to inspect it. Many of his blades have interesting horimono of dragons, which is something originally found in the work of Nagamitsu though not so frequently, so seems to be something he further developed on his own. He worked mostly with two styles of hamon, one in suguba which was the overall style of the late Kamakura period and which he inherited from his father, and another called kataochi-gunome which resembles horse teeth. This is basically a gunome hamon with the heads cut off, making a suguba in the upper but gunome in the lower. This seems possibly to have been an advancement in making the blade less fragile by reducing tempered material, though this is only speculation now. We almost never know why these smiths do what they do, though it is fair to assume that improving performance was always a goal in the koto period as the swords would always be subject to a lot of use. He is also noted as having made some items with very strong utsuri in the jihada.

Kagemitsu as a tanto maker made a fair number of them, but he seems to have made them a lot longer than his peers like Rai Kunitoshi. These tanto that are longer than 26.5 cm are called sunnobi tanto, and his longest is a bit over 30 cm. Unfortunately many of these were shortened in later times. In the Muromachi period many tanto were around 22-23 cm as were tanto in the Nanbokucho period (which saw tanto diverge into a smaller size around 22 cm with smiths like Samonji and Shizu, and larger size that surpassed 30 cm and were made by smiths like Kanemitsu, Hiromitsu and Akihiro).

Many of these suriage tanto, in spite of this condition issue, went on to pass Juyo. Some of them were shortened enough to cut off part of the signature, so he has blades that just end with Osafune with having the rest of his name cut off. But still they have passed Juyo due to the masterful workmanship. There are 34 Kagemitsu tanto that passed Juyo and higher, and 11 of these lost part of the mei through this shortening and maybe six others were shortened a bit in the nakago. The majority of these have the machi moved up a bit to adjust the length of the blade as well.

Fujishiro says that he worked for about a 30 year period, and we see dated work that documents this period today. His last blade is dated a little bit into Nanbokucho at 1334, and his first comes right at 1305 (the last Nagamitsu dated blade found so far is 1304). Fujishiro ranks him as Sai-jo saku for grand-master levels of skill, and bear in mind that to be a grand-master in the Kamakura period is to be a grand-master when surrounded by the other smiths of the golden era of sword-making.

Kagemitsu's hallmark feature is beautiful jihada, for which he has obtained a great deal of fame, as well as the kataochi gunome hamon that is synonymous with his name.

Kagemitsu forges extremely fine and dense ko-itame-hada with fine ji-nie and the jigane is very clear and looks beautiful. He has won an established reputation that he forges the best quality jigane among the Osafune smiths and an old sword book ‘Shinkan Hiden 9 Token Bijutsu 533 Sho’ says, “His jihada looks like nashiji-hada.” Token Bijutsu

Kagemitsu forges the finest ko-itame-hada with thick ji-nie and the clearest jigane in the Ko-Osafune school. Hinohara Dai, Token Bijutsu

Kagemitsu's work has been highly sought after through the centuries, with his swords being given to and from the Shogun, such as Shogun Iemitsu giving Sakai Tadamasa a Kagemitsu tanto (listed as a wakizashi, so probably one of his long works in tanto form). I could at least 15 other such gifts in the Tokugawa daybook. His influence lasted from his time in smiths like Motoshige all the way to the Shinshinto period where his work was copied by Naotane and Munetsugu.

Detail of Juyo Ko-Osafune Kagemitsu Tanto
Ko-Osafune Kagemitsu Tanto PapersKo-Osafune Kagemitsu Tanto Hozon

Kagemitsu Tanto

This beautiful tanto is in the suguba style of Kagemitsu and is one that retained most of its length. Tanobe sensei points out in the sayagaki that it is a rare sunnobi tanto by this smith. I noted above that a large percentage of Juyo tanto by Kagemitsu are flat out suriage now. Only 8 of the 34 Juyo are left in sunnobi length, so this is one of the longer tanto still in existence by the smith. Unlike many of the Juyo, this one has an intact long signature though the second character got punched out during mounting a koshirae long ago and is now partially filled with gold.

The most outstanding feature of this blade is the vivid utsuri which can be seen from the other side of the room. He did not make horimono on this blade and instead choose a quiet hamon so it probably dates from the middle period of his work, before he fully developed kataochi gunome.

The forging quality is also outstanding as can be seen in the photos. The jihada is tight and beautiful and is completely in keeping with the great work of this smith.

This tanto is also accompanied by high quality koshirae. The fittings are papered Hozon to Kyo-Kinko school (Kyoto Goldworkers). This is a fairly wide attribution that covers all of the Kyoto schools, and I think could be made more specific. The kozuka in particular reminds me very much of Umetada school work, and I have a reference example to show. The theme is gold kiri mon with shakudo, and the inlay of the kozuka is quite nice with the kirimon being a free floating element.

Brian Tschernega is an NBTHK award winning goldworker with universal praise. His habaki have graced several Tokubetsu Juyo blades and last year I sent in a Yukimitsu for a client which passed bearing his habaki. Brian did the mounting for the tosogu and did the lacquer work, as well as making the solid gold shitodome that hold the kashira on place. It is a stellar job and very much respects the quality of the blade. Even the mekugiana is gold as I asked Brian to do the best possible job for this great piece.

Ko-Osafune Kagemitsu Tanto KoshiraeKo-Osafune Kagemitsu Tanto Tsuka

I have this tanto now in Japan awaiting Juyo shinsa in September. If it is sold before then I will pay for the submission and handling fees on behalf of the buyer. The tanto passed Juyo for the buyer as predicted.

For a tanto collector, this is a very rare and important specimen of one of the best makers of all time. I highly recommend it.

Ko-Osafune Kagemitsu Tanto Oshigata

Juyo Token

Update: This blade passed Juyo for the buyer in session 63. The oshigata and description are below.

Jūyō-tōken at the 63rd jūyō shinsa held on November 17, 2017

tantō, mei: Bi__ Osafune-jū Kagemitsu (備○長船住景光)


nagasa 27.0 cm, only a hint of sori, motohaba 2.1 cm, nakago-nagasa 10.7 cm, nakago-sori 0.1 cm


hira-zukuri, mitsu-mune, normal mihaba, just a hint of sori


dense ko-itame with plenty of ji-nie, fine chikei, and a faint utsuri


hoso-suguha in nioi-deki with ko-nie that is mixed with a little bit of ko-gunome, ko-ashi, and kinsuji


sugu with some hakikake and a brief ko-maru-kaeri


ubu, kurijiri that tends to ha-agari, katte-sagari yasurime, two mekugi-ana, the sashi-omote side bears centrally under the first mekugi-ana a finely chiseled seven character signature


Kagemitsu (景光) was the son of Nagamitsu (長光) and the third Osafune main line generation. He became famous for perfecting a hardening in kataochi-gunome. As for dated works, these range from Kagen (嘉元, 1306-1306), i.e. the end of the Kamakura period, to Kenmu (建武, 1333-1338), i.e. the early Nanbokuchō period, and represent thus an active period of at least 30 years. His workmanship is hardly as flamboyant as that of Nagamitsu as he mostly hardened a suguha-chō that is mixed with slanting gunome elements or a ha that is based on kataochi-gunome. In other words, his style is more calm than that of Nagamitsu but it has to be pointed out that the forging quality of his kitae is occasionally superior to his father’s. Another characteristic feature of Kagemitsu is that he made noticeably more tantō than Nagamitsu of whom only few such blades are extant.

This tantō is of a sugata that features a hint of a sori and shows a finely forged kitae in a dense ko-itame with plenty of ji-nie and a faint utsuri. The hamon is a uniformly hardened hoso-suguha that is mixed with a little bit of ko-gunome and ko-ashi and thus we have here a highly elegant work whose interpretation of the jiba reflects very well the classical style of Kagemitsu.

Ko-Osafune Kagemitsu Tanto Sayagaki


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

  1. 備前國長船景光
    Bizen no Kuni Osafune Kagemitsu
  2. 長八寸九分
    nagasa 8 sun 9 bu
    nagasa 27.0 cm
  3. 七字銘有之
    shichiji-mei kore ari
    It is signed with a seven character signature.
  4. 同工ニ間々経眼スル静穏ナ直刃ノ作域而典雅ナ趣アリ身幅ノ割ニ目立ッテ寸延ビタ 姿態モ同工ニハ珍敷ク好資料也
    Dōkō ni ama keigan-suru seion na suguha no saku’iki shikamo tenga na omomuki ari mihaba no wari ni medatte sunnobita shitai mo dōkō ni wa mezurashiku konomi shiryō nari
    It shows a calm suguha, a feature that is occasionally seen on works of this smith. The workmanship is of an overall rather classical and refined interpretation and the work is also an important reference for the smith as considering the length and width, it is a rare blade that is made in sunnobi dimensions.
  5. 探山邉道識惟时乙未仲呂
    Tanzan Hendō shirusu (kaō) kono toki kinoto hitsuji churyō
    Written by Tanzan Hendō in April of the year of the sheep of this era (2015) + kaō