Ko-Osafune Nagamitsu KatanaKo-Osafune Nagamitsu

periodLate Kamakura (ca. 1295)
designationNBTHK Juyo Token Katana
ratingSai-jo saku, Ryo-wazamono
Shogen Nagamitsu
Kunzan (kao)
nagasa72.9 cm
sori2.4 cm
motohaba2.8 cm
sakihaba1.8 cm
kissaki3.1 cm
nakago nagasa19.1 cm
nakago sori0.2 cm
price -sold-

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

The greatest of all schools is the Osafune school of Bizen province. It lasted for 350 years of continuous sword production. 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 Osafune span over 500 years.

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

As listed above, the initial four generations of the Osafune school are:

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

Mitsutada is a smith who's greatness is beyond description and can be read about here on my site. His work was in a style very similar to the contemporary Fukuoka Ichimonji smiths of the middle 1200s. They were broad, masculine, and flamboyant choji style tachi, many of which are cut down today and have lost their signatures. There are 10 Tokuju, 14 Jubi, 16 Juyo Bunkazai and 3 Kokuho left to us by Mitsutada, which are truly astounding counts given the rarity of his work today (there are in comparison only 21 Juyo, so there are more upper ranked blades than Juyo blades by this smith).

Detail of Juyo Ko-Osafune Nagamitsu Katana

Old Bizen blades such as Ko-Bizen, Ichimonji, Osafune Mitsutada or Nagamitsu all have much to be seen in the blades and one just cannot put a blade like these down right away, there being so much to see. Yamanaka, Nihonto Newsletters

Mitsutada's son Nagamitsu is the second of the mainline Osafune smiths. Nagamitsu's initial work looks quite like Mitsutada, but toward the end of his life it becomes quieter with special developments approaching suguba, and focusing more on gunome than on choji style. Nagamitsu is the smith from the koto period who has the most top ranked blades of all smiths to have lived. There are 25 Tokuju, 40 Juyo Bijutsuhin, 29 Juyo Bunkazai, and 6 Kokuho by Nagamitsu for a total of 98 top ranked blades. One of the reasons for Nagamitsu's high count is that he trained and developed many master smiths to work in his forge. The best of them was his son Kagemitsu, but also in the forge were his brother Sanenaga, and their collective students Nagamoto, Sanemitsu, Nagamune, Nagachika, Nagamori, Chikakage, and Norimitsu.

These smiths are all ranked between Jo-saku and Sai-jo saku, and the collective output was overseen by Nagamitsu. As well, around the time of the end of Nagamitsu's production period the Hatakeda school merged with Osafune so he is likely to have incorporated them under his aegis as well. Hatakeda Morishige is listed as one of his students, and Nagamitsu's student Mitsukane left Osafune and became a student under Rai Kunitoshi. The amount of talent under one roof under Nagamitsu is staggering, and the significant output quality blades under him has never been surpassed.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Kagemitsu did not drop off in any skill from his father when he inherited the forge (the NBTHK has written that his skill in forging jigane is higher than Nagamitsu). As Nagamitsu worked with his brother and student Sanenaga, Kagemitsu worked work his brother and student Kagemasa. Kagemasa blades were sometimes shortened just at the last character of the signature which I believe was a strategic shortening that would allow them to be presented as works of Kagemitsu. Kagemitsu's son was Kanemitsu, who was a major talent and one of the all time greats, and his second son Yoshimitsu is also very highly ranked and regarded. Motoshige is thought to be a son of Hatakeda Morishige, and his initial style was nearly identical to Kagemitsu. His younger brothers Shigezane and Shigemitsu are also said to be students of Kagemitsu, so we see again many great master smiths working together under Kagemitsu as they did under his father.

Kanemitsu took over as the fourth master of Osafune, and by the Nanbokucho period when he peaked in skill, all of the other schools in Japan were starting to fade. Soshu was in its denouement, 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.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Ko-Osafune Nagamitsu

Nagamitsu had the personal name of Saemonnojo and a clan name of Fujiwara. He is known as one of the greatest Bizen smiths of all time, and he had three forms of genius. The first is that he was able to work in his father's style to the same level of quality and skill, and afterwards exceed it. The second is that he did not remain locked into what he learned, but evolved and developed and refined his style throughout his lifetime. The last is that he can be recognized as one of the greatest teachers in this domain to have lived, which we can see by the number of master swordsmiths he trained and who worked under his roof.

Takase Nagamitsu
Takase Nagamitsu

The o-choji midare is often regarded to equal those of the Fukuoka Ichimonji, though the edge of the hamon will be made very distinct and sharply. The workings within the hamon have much to be seen and enjoyed. Those made very vigorously are like that of Mitsutada with many variations in the workings. Large pattern inazuma are seen. The suguha choji midare are made like those of Rai Kuniyuki of Yamashiro Province and Niji Kunitoshi and in many cases, they are made superior to those two. Workings within the hamon are found in numbers.

Blades whose hamon is worked in o-choji midare will have the steel in o-mokume hada and these will have jifu utsuri. Blades whoso hamon is worked in suguha choji will have the steel in ko-mokume hada tightly knit and there will be large patterned hada areas and in these there will be jifu utsuri. The utsuri which is the trade-mark of Bizen smiths, especially by the early smiths of Osafune and previously by the Ichimonji smiths are considered the ultimate and in the case of Nagamitsu, it is considered to be one of the best. Yamanaka, Nihonto Newsletters

Nagamitsu is a smith from the middle to late Kamakura period. The earliest dated work of Nagamitsu is one of Kagekatsu's 35 great treasures of the Uesugi clan, and has a date of 1274 on it. The signature is Osafune Nagamitsu, and is I think the second earliest dated work naming Osafune as the production center in Bizen (The earliest is a work of Hatakeda Moriie with a 1272 date). It bears the name Takase Nagamitsu and is pictured to the right. At times the unusual signature and date have caused it to be held in some doubt, that the date and Osafune part may be ato-mei from a later period, but the information they convey is accurate.

This blade is already showing the transition to middle period Nagamitsu style, where the blade is moderately shaped and the hamon has lost some of the wildness of earlier works. Today this sword is Juyo Bijutsuhin and is in the Uesugi museum in Japan. Prior to this works are signed in two characters usually and the shape is middle Kamakura period. Because of this, we should probably be thinking of his career starting around 1260.

It was more common for Nagamitsu to date his works toward the end of his career, and many of these have nagamei of Bizen Kuni Osafune ju Nagamitsu. Some have this same signature but are lacking the ju character and others have a signature styled Bizen Kuni Osafune ju Sakon Shogen Nagamitsu Zo. The Zo is interesting as this was infrequently used by his father Mitsutada, and is something that was also found in Hatakeda works.

Detail of Juyo Ko-Osafune Nagamitsu Katana

For signed koto masterpieces that exist, Nagamitsu ranks in first place of all smiths. This is in part due to the large forge that he built and that his students were so highly talented and able to increase the production that the group was responsible for. And the other part of it is simply that his work has been held in the highest regard since the time of its manufacture, and because of this, a good number of masterpiece blades were preserved over the centuries.

His style evolution is thus:

  1. Grand and wide sugata of the middle Kamakura period, with choji midare hamon of varying height.
  2. More modest sugata transitional to the late Kamakura period, with choji hamon and rounded tops and gunome mixed in, with controlled height.
  3. Gentle sugata with noticeable tapering, of the late Kamakura period, with very refined jihada and hamon tending to suguba.

Works at the beginning of his career will tend to have bohi and works at the end introduce more horimono elements, such as dragons and bonji. This final style is handed to Kagemitsu who continues to develop it.

Though we appreciate the florid choji of Ichimonji, Mitsutada and Nagamitsu, Fujishiro relays the following reasons that it was abandoned (to summarize, Nagamitsu carefully lowered the height of his hamon over his career in order to improve the durability of blades in combat):

Detail of Juyo Ko-Osafune Nagamitsu Katana

The most exuberant ō-choji of Ichimonji, Tadamitsu nado can be seen in the early period of Nagamitsu, but in the later period, sugu choji, in other words, choji distributed in suguba, was predominant. There is no disagreement that this was a change in the style of production, but there is a splendid reason. A story written a long time ago says. In the exuberant ō-choji like that of Ichimonji, in general, the yakiba is wide, those in which the yakigashira reaches the shinogi are said to break in actual combat. In attempting to apply the subdued sugu choji of Nagamitsu, the tsuchi tori of the suguba is further added to the tsuchi tori of the choji, and when the yakiba moves across, the yaki does not extend beyond the boundary of that suguba. It can deduced that Nagamitsu took care that the yakiba did not become wider than that. Fujishiro Yoshio

We can see from this that the primary concern of Nagamitsu was in making the style of sword he was taught to make, more robust and less likely to fail when in battle. He is probably at the very top rank of the combination of functional, reliable blades with beautiful manufacture as a result. Though the most flamboyant of these blades are those that tended to get rankings as Juyo Bijutsuhin and Juyo Bunkazai, the greater part of the Kokuho blades are the more controlled and refined style from his middle period and first half of the end.

More than twenty year ago, a “Nagamitsu Exhibition” was held at the Sano museum. At that time, they displayed about 160 Nagamitsu blades. According to the report, today 10% have an omidare hamon mixed with big choji and kawazuko choji; 45% have a choji and gunome hamon: 20% have a smaller hamon such as ko-choji and ko-gunome; 25% are suguha or have a suguha type hamon. NBTHK Token Bijutsu

Nagamitsu put the roots of kataochi-gunome into his very few tanto and naginata that exist, but he never put it into swords. His son Kagemitsu made many more tanto and replicated and refined this hamon, and then carried it into his swords as well.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Sakon Shogen Nagamitsu

He is the son of Mitsutada, and is of the legitimate line of the Osafune Kaji, which is the one to which the majority of the Bizen Kaji belong. He is called Saemonnojō, and as for Sakon Shōgen, the prevalent story is that this was the nidai, but I think they are the same person. Fujishiro Yoshio

Fujishiro was somewhat of a pioneer in dismissing multi-generational interpretations of older koto smiths. It was not until the last 30 years that these theories have become dominant. The Juyo Token publications have been essential in this, as they have exposed and published large numbers of old smiths' works and allowed us to see the big picture. That big picture shows one of stylistic evolution throughout the smiths lives, and previously this kind of change in style has usually (and incorrectly) been ascribed to handoff to a second generation.

At the time of manufacture of these blades by Nagamitsu and Rai Kunitoshi there was no confusion about the number of generations. The NBTHK wrote that in the case of Rai Kunitoshi at least, the old books are not confused either, they list one generation up until the Muromachi times. After a few centuries of lost works, signatures being cut off, and so on, the stage was set for some fogginess on the details and it is around the end of the Muromachi period when theories about second generations were introduced and it is only recently that they have been dismissed.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Logically, it follows that any second generation inherits first the style of their teacher or father, and continues that before their own experience takes over and they in effect, become their own teacher. It is always this way, where early works of Norishige are not the flamboyant explosions of activity of his later work. Inoue Shinkai's initial work signed under Kunisada just looks like his father's work. In addition, at the end of master smiths' lives their work span is almost always extended by the presence of a master student who takes over the grunt work of production and in many cases signs the master's name on his behalf. This sharing of the workload meant that master smiths could be productive into their 70s and 80s. In the case of Rai Kunitoshi in the early 1300s, he was signing works with his age of 75 and Yosozaemon Sukesada did this as well in the 1500s, signing a work at the age of 74. Given the state of medical knowledge 500-800 years ago, it is a miracle that they were even alive, let alone working and prosperous. Even today, we view someone who is working hard in their 70s as an unusually healthy person.

Anyway the point of this is that a student always learns their teacher's style first, because this is what the teacher has to teach. As such it is not a logical conclusion that a style change necessarily signifies a generation change. Rather, a style change should in fact indicate a smith's personal evolution and the demands of the market and changing times around that smith. This evolution means that if we look at late work of one smith vs. his earliest work, the styles should not match, where late work of a smith will match the earliest work of his best students. Over time that following generation will also undergo a stylistic evolution and at the end of his work period we should be able to now say that yes, his style evolved away from his teacher and in this way there is separation between generations.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Generally speaking, Sakon Shogen Nagamitsu tempers midare-ba in small pattern, meanwhile the first generation tempers gorgeous choji-midare mixed with gunome. Sakon Shogen Nagamitsu tempers sugu-ha with choji ashi but occasionally practises gorgeous and vivid workmanship like the one with the date of the second year of the Sho-o Era that is designated as Juyo Bunka-zai and owned by the Hayashibara Museum. The works of Sakon Shogen Nagamitsu with the dates of Sho-o 2, Einin 2, Einin 5 and Kagen 2 have been confirmed. Inferring from these dates, it seems to be that Sakon Shogen Nagamitsu is the signature of Nagamitsu used in his later years.

As a result of survey of the signatures, little difference in chiselling style can be found in the two characters Naga Mitsu between the two different type of signatures. Furthermore, how it can be explained that Kagemitsu succeeded Nagamitsu as the third generation of the Osafune school despite a 2nd Nagamitsu existing? [i.e. 1st and 2nd generations can only be one smith -db] Also it is very doubtful that there was a custom to succeed to the smith name of the former generation in those times.

The oldest date (1274) of Nagamitsu is recorded on the tachi nicknamed Takase Nagamitsu designated as Juyo Bijutsu-hin and owned by the Uesugi Museum in Yonezawa City. His latest date is Kagen 2 (1304) and his active term becomes is 30 years if the date (1274) is [accurate]. After all, it can be possible say that [the meito/meibutsu] Tsuda Totomi Nagamitsu and Daihannya Nagamitsu are examples of his earlier works than the Takase Nagamitsu. Not only Nagamitsu, but also other smiths of that period came to make normal tachi-sugata with narrow hamon in small pattern after the Sho-o and Einin Eras. Taking into account the above theory, it can be concluded that there was only a [single] Nagamitsu and the second generation did not exist. Tanobe Michihiro, NBTHK Token Bijutsu

Detail of Juyo Ko-Osafune Nagamitsu Katana

In the case of Nagamitsu, many of his works from the end of his career have the formal title Sakon Shogen added to them. This along with the style change has made past authors and experts believe that this was a second generation of Nagamitsu.

These dated works exist with given signature types:

1274Osafune NagamitsuBunei 11 jugatsu hatachigo hiBijutsuhin
1285Bizen Kuni Osafune Nagamitsu zoKoan 8 rokugatsu hiJuyo
1293Bizen Kuni Osafune ju Sakon Shogen Nagamitsu zoEinin 1 junigatsu hiJuyo
1294Bizen Kuni Osafune Junin Sakon Shogen Nagamitsu ZoEinin 2 kinoe uma nanagatsuJuyo
1297Bizen Kuni Osafune ju Sakon Shogen Nagamitsu zoEinin 5 sangatsu hiJuyo
1297Bizen Kuni Osafune ju Nagamitsu sakuEinin 5 sangatsu hiJuyo
1289Bizen no Kuni Osafune ju Sakon Shogen Nagamitsu zoShoo 2 tsuchinigoto rokugatsu hiJuyo
1289Bizen Kuni Osafune ju Sakon Shogen Nagamitsu zoShoo 2 jugatsu hiBunkazai
1300Bizen Kuni Osafune NagamitsuShoan 2 nigatsu kichijitsuBunkazai
1301Bizen Kuni Osafune ju NagamitsuShoan 3 gatsu hiJuyo
1301Bizen Kuni Osafune ju NagamitsuShoan 3 junigatsu hiJuyo
1302Bizen Kuni Osafune ju NagamitsuShoan 4 rokugatsu hiJuyo
1302Bizen Kuni Osafune ju NagamitsuShoan 4 kyugatsu hiJuyo
1303Bizen Kuni Osafune ju NagamitsuKagen 1 jugatsu hiJuyo
1304Bishu Osafune ju NagamitsuKagen 2 hachigatsu hi - hachiman daibosatsuBijutsuhin
1304Bizen no Kuni Osafune ju Sakon Shogen Nagamitsu zoKagen 2 juichigatsu hiJuyo
1304Bizen Kuni Osafune ju NagamitsuKagen 2 junigatsu hiJuyo
1316Bizen Kuni Osafune ju Naga~Showa 5 sangatsuJuyo

Notes: The 1316 work has the mei cut off before the final character, so there is DEN added to this attribution out of caution. The 1274 work, the general feeling is that the date and Osafune were added on as atomei.

What is clear from this is that there is no separated period where Sakon Shogen signatures follow Nagamitsu signatures, and thus it deflates any argument that Sakon Shogen must be a following generation. Rather, Nagamitsu had some reason for adding his title to these blades. Possibly they were special order blades, following the same logic as the Sue-Bizen smiths who added their personal name to blades in this situation.

The work style of those signed Sakon Shogen also contain those with pure suguba hamon, and the very last one with a date is one of these. At this time the Rai school had also abandoned choji style hamon for suguba so we can take that as a sign of the times. Since suguba was around forever and these blades also call back to earlier more gentle sugata styles, it seems to have been a trend of the times to throw back to early Kamakura and late Heian styles.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Hamon: suguha choji midare worked in nioi with deep ashi. There, also, are works with narrow yakiba with small pattern worked in nioi with ko-midare and the peaks of the midare will be in togari from the top of which the nioi spreads into the ji beginning ji utsuri. This occurrence is not seen on any swordsmith's work prior to the 2nd [Sakon Shogen] Nagamitsu [i.e. it is his invention -db]. There, also, are chu suguha with ko-midare mixed in and which is made in saka style (reverse) and in some works, the saka ashi within the suguha are seen along the entire length of the hamon.

Jitetsu and Hada: Very finely worked steel results in various patterns depending on the type of hamon made ... that is, Nagamitsu 2nd made certain types of hamon on the blades with a certain type of grain. Those with large pattern grain steel will have the hamon in ko-choji midare or ko-midare and these will have choji utsuri. Those with ko-mokume hada will have the steel tightly knit and on these there will be jifu utsuri and there will be chikei in addition. Those blades with suguha will have choji utsuri. Yamanaka, Nihonto Newsletters

He changed from ō-choji to sugu choji, then in his later years when he took the name of Sakon Shōgen, he made suguba and sugu ashi iri. Rai Kunitoshi nado of this same period changed from an exuberant choji ha to the suguba type. This was not a period of deterioration in technology due to changes in generation, but was something that was demanded. This is clear when you see the prosperity of Nagamitsu and the Kunitoshi Mon.


The reason Nagamitsu, Kunitoshi nado made the suguba can be thought of as being from a viewpoint other than practical use, but there was probably in fact some influence from the tōken of the Nara period. Fujishiro Yoshio

Detail of Juyo Ko-Osafune Nagamitsu Katana

Another hallmark of Sakon Shogen works is a more refined and beautiful jihada, which show that the transition in the second half of his life was a conscious stylistic choice. Most of the skill a smith has to offer is shown in the forging and a great hamon by necessity has to begin with well forged steel, and in this regard Sakon Shogen works are highly superior within the body of work of Nagamitsu.

The NBTHK for the first half of its existence continued to document blades as first or second generation Nagamitsu, with Sakon Shogen thought to be the second generation. In the last 30 years this has been abandoned and such blades are now just stated to be by Nagamitsu. So when considering this in NBTHK Juyo papers, we have to keep in mind that every year, new knowledge refines past knowledge, and this determination to a second generation of Nagamitsu has now been voided. All of them are simply Nagamitsu and those marked as 2nd generation or as Sakon Shogen need to be understood as work from the end of his career. There is some argument that there could be a nidai Nagamitsu still, but that the nidai comes after Sakon Shogen. There is not much support for that theory of a nidai currently, and I think maybe these could be daimei by his students. Regardless the conclusion is still that Sakon Shogen is the Shodai Nagamitsu.

Detail of Juyo Ko-Osafune Nagamitsu Katana

Some of the swords inscribed with the Sakon-Shogen mei are dated from Shoo (1288-92) and Einin (1293-98) times. These signatures consist of completely identical chisel strokes as the Shodai of Nagamitsu in the two-generation theory [i.e. First generation Nagamitsu and Sakon Shogen Nagamitsu are the same person -db]. The blade characteristics include the hamon comprising compact midare with narrow intervals. The hamon width is so varied as to appear more exuberant than the Nidai's. Therefore, by comparison, it would seem more natural and appropriate to take Shogen Nagamitsu as identical with the Shodai in his very last years. Tanobe Michihiro, NBTHK Token Bijutsu


Old books say that when Nagamitsu retired and abdicated the forge to the second generation, he took on the name Junkei and continued making swords. Today this is dismissed and Junkei is understood to be a different smith. There are older publications which repeat this, and when people cite these old works in their research, they are repeating something that is now out of date. So this is something again to take note when studying the smith and considering blades.

Since the early Muromachi period, there has been a theory that Junkei was Osafune Nagamitsu’s priest name after he became a priest or monk. Examples were listed in books such as the Noami Hon, the Chokyo Meizukushi, and the Okin sho. But after the 2nd world war, this theory was questioned by some scholars. After examining Junkei’s work, the opinions were that that he was a different person from Nagamitsu. NBTHK Token Bijutsu

That said, there are only very few works of Junkei that exist (one mumei, two signed Juyo, two signed Juyo Bijutsuhin and two signed Juyo Bunkazai), so we are not likely to encounter them so much.

Detail of Juyo Ko-Osafune Nagamitsu Katana
Ko-Osafune Nagamitsu Katana Sansaku Boshi

Sansaku Boshi

The most key kantei point when assessing Nagamitsu work is the presence of the sansaku boshi. This boshi is basically suguba with a bulge in the middle, and comes along as his style evolves away from his father. It takes its name from the three makers who specialized in it: Nagamitsu, Kagemitsu (Nagamitsu's son) and Sanenaga (Nagamitsu's younger brother).

It can be seen in some other makers' work, and Kanemitsu can make it too in his earliest work that looks like Kagemitsu. But for the most part this boshi is a short circuit on kantei that should make you be thinking about Nagamitsu first to see if it fits, then the other two, and after, any other smith.

The fact that the bōshi of the Nagamitsu Ha is narrow notare, is turned back in ko-maru and is tightly packed is known as a commandment of Kantei, but one must take notice that bōshi just like that can also be seen in the Shōsōin (Ancient Store House of Japanese Cultural Treasures). Of course, there is no direct connection between the two, but this beautifully made bōshi was already in existence in the Nara Jidai, and along with the very narrow suguba, it became a pattern for later times. Nihon Kotōshi (History of Old Swords of Japan)

Not all Nagamitsu works have this, as it is an evolution that he introduced. Earlier work will not show it, and if he recreated earlier work styles later in life as throwbacks, then these will lack it as well.

Detail of Juyo Ko-Osafune Nagamitsu Katana


Today, there are many works of Nagamitsu that exist, but they are mostly not on the market as high level collectors snatch them up and hold them. Even so from time to time we can see them.

His total of 74 Jubi to Kokuho works (40 Jubi, 29 Jubun and 6 Kokuho) is 50% more than the second smith on the list (Rai Kunimitsu). This points again to a combination of high skill, productive school, and centuries of high regard that preserved them. For Juyo works he is fourth overall with 161 passing, 25 of which went on to Tokuju and putting him sixth on that list. The large number of higher ranking blades with Ministry of Education papers though folded in with the Tokuju works easily ranks him first overall.

Totomi Nagamitsu
Totomi Nagamitsu

The proof of this regard is also known by the fact that many of these Nagamitsu have preserved information about the daimyo collections they came from. Every major daimyo treasured at least one Nagamitsu blade, and the surviving items come from the Asano, Ikeda, Date, Makino, Mizokuchi, Hosokawa, Honda, Ishikawa, Tokugawa, Matsudaira, Nabeshima, Shimazu, Suge, Shozo, Tachibana, Uesugi, Yaguyu and Yamanouchi clans. Some Nagamitsu were personally treasured by various generations of the Tokugawa shoguns, in particular Tokugawa Ieyasu. As well, Oda Nobunaga and Toyotomi Hideyoshi treasured Nagamitsu. Many of these blades are meito and meibutsu such as the Kanna-giri Nagamitsu, Dai-hannya Nagamitsu, Tsuda-Totomi Nagamitsu, and the Nikko Nagamitsu.

Although suriage, both the ji and ha [of the Tsuda-Totomi Nagamitsu] are excellently executed and the hamon, especially, is quite equal to Dai-hannya's work. This example as a whole is equal, if not better, to the signed Mitsutada examples illustrated in this book. Dr. Honma Junji, Great Masterpieces of Japanese Art Swords

Some of these important examples are in museums such as the Tokyo National Museum and the Sano Museum. Some are privately held and others are in shrines and these blades are not accessible to the market. For instance the Azuki Nagamitsu was owned by Uesugi Kenshin and donated to the Toshogu shine, where he prayed for the health of his family. Once in the shrines, these blades are preserved from shortening. Like many of the Uesugi blades, this one was left ubu and long.

Another of the finest works of Nagamitsu is the meito Sansho Gongen Nagamitsu. Nagamitsu wrote Kumano Sansho Gongen into the signature, as it seems to have been a special dedication piece for the Kumano shrines, which were administered by the Kuki clan. The Kuki likely had control of the blade since its manufacture by Nagamitsu. As such it is a particularly mint condition work of Nagamitsu and Ieyasu treasured it. This blade was given to Oda Nobunaga by the Kuki, and from there found its way to Toyotomi Hideyoshi, then Uesugi Kenshin and then to Tokugawa Ieyasu. It is currently privately owned by one of the top collectors in Japan.

Sansho Gongen Nagamitsu
Sansho Gongen Nagamitsu

With all of this, it is no surprise that Nagamitsu retains a Sai-jo saku ranking from Fujishiro and a very high valuation of 2800 man in the Toko Taikan (12th highest over all smiths and 4th overall Bizen smiths, behind Mitsutada, and Ichimonji Norimune and Yoshifusa). It is lesser known that his blades were also excellent cutters.

Detail of Juyo Ko-Osafune Nagamitsu Katana

The war chronicle to the five Battles of Kawanakajima which was published in the tenth year of Keichoo (1605) says that [Uesugi] Kenshin had pushed away [Takeda] Nobushige towards the riverbank of the Chikumagawa [river], attacking him with a sword of Nagamitsu. Nobushige was not able parry and Kenshin severed his left leg at the thigh, whereupon he fell from his horse and broke his neck. Markus Sesko, Legends and Stories vol 1

The Date family also owned a sword from the former possessions of the Usami family (宇佐美) who were introduced in chapter 9. The piece in question is the meibutsu Usami-Nagamitsu (宇佐美長光). It was once worn by Usami Takatada (宇佐美孝忠), lord of Biwajima Castle (琵琶島城) in Echigo province. It is said that he cut through the hilt of a yari and right through the skull and mouth of an enemy with this sword. Markus Sesko, Legends and Stories vol 2

As a result of this degree of sharpness, Nagamitsu has a Ryo-wazamono ranking for outstanding cutting ability.

Juyo Token Ko-Osafune Nagamitsu Katana

Juyo Token Ko-Osafune Nagamitsu Katana

I feel that the Nagamitsu works show a dynamic hamon with interesting activities, and the beautiful forging techniques that he handed down to his son Kagemitsu. Kagemitsu in particular is held up as an exemplar of fine jihada and he learned this at his father's knee.

In this regard this blade does not disappoint whatsoever. The jihada is simply gorgeous and has vivid midare utsuri throughout that makes it a real joy to appreciate. The hamon is the smaller dimensioned choji midare inherited from Mitsutada, and this lets us place the blade in the middle of the last half of Nagamitsu's life. The length is excellent still at 73 cm and it must have been about 85 cm before it was shortened. Even so it preserved a deep curve and the horimono remains above the habaki where it can be appreciated.

This sword also shows a clear sansaku boshi and the rest of the construction and style make the attribution far beyond question. This is I think the most secure a mumei attribution can be, because there are no doubts about it whatsoever. The kitae is so fine that it appears like silk, and this I think is done to give the best ground for the interesting utsuri that is present in this blade.

It has an older period Juyo paper from session 21, before the NBTHK stopped differentiating between generations of Nagamitsu. The work style corresponds to the Sakon Shogen period, so it passed Juyo as Sakon Shogen Nagamitsu. After it passed Juyo, the owner requested Dr. Honma to add a kinzogan mei to it, and so it now bears the signature Shogen Nagamitsu along with Dr. Honma's mei Kunzan and his kao. When I have researched these in the past, they have been work done by Gassan Sadaichi, the Living National Treasure swordsmith at Dr. Honma's request so I think that is the case with this one. After this was done the blade was resubmitted to Juyo to get a new paper, so there are two oshigata for it. One with the kinzogan mei and one without, and this is also a nice opportunity to remind oneself that oshigata are an interpretation of a blade. You can see there are differences between the oshigata, which is attributable then to different artists doing the work.

This blade has horimono of a kurikara (dragon) and the characters Hachiman Daibosatsu on the opposite side with a rendai. Hachiman is the god of war, and was thought to provide guidance to warriors. These horimono are quite rare as there are only three others by Nagamitsu that have kurikara that passed through the NBTHK. The Hachiman Daibosatsu inscription is usually something we find on blades intended for donation to shrines. There are some examples of Nagamitsu's work with this written into the nakago and there is at least one famous one by Kagemitsu that belonged to Uesugi Kagekatsu. Whether that was liberated from a shrine or just made like that for use, I am not sure. Anyway both the dragon and Hachiman inscription are the kind of horimono that are also seen on the work of Kagemitsu. So it was either influential on Kagemitsu, or he was the craftsman responsible for handling horimono in the Nagamitsu workshop. Either way, it is a very nice bonus to have Kamakura period horimono like this, and these are among the earliest examples of kurikara on Bizen tradition swords. There are in fact only two blades known with earlier kurikara horimono like this, both Ko-Bizen swords. So it is really something unusual to cherish.

I brought the sword to Tanobe sensei to make a sayagaki for it. When I showed him the oshigata he immediately pulled out an oshigata of one of the Kokuho blades and compared the similarities in some sections. After this he wrote an unusually long sayagaki on the back (Dr. Honma's sayagaki is on the front) as the blade impressed him. He ran out of room in fact, and had to extend to three columns. He said in this sayagaki that the hada is exquisite and it reflects the true style of Nagamitsu from the late 1200s.

The blade is beautifully polished in sashikomi style which is very appropriate for this sword. However there are some scratches in the kissaki of this blade, and I will get those resolved shortly.

For someone who wants a good example of utsuri, this would be a great blade to have. This is one of the features of Bizen swords that makes them stand apart, so if you can get something like this it is really good for a collection. Utsuri is a rather mysterious feature. My recent conversations in Japan, I heard an opinion that the reason for utsuri was to semi-harden only the outer shell of the blade. This surface hardening made the blade more robust in resisting bends, as the primary structure and design of Bizen swords is meant otherwise to prevent breakage. As Nagamitsu seems to have evolved his style over the years to make a blade more capable of handling stress, it may be that the emphasis on utsuri in the later part of his career goes hand in hand with controlling and reducing the overall height of the hamon, not just for appearance but for function.

Varying Appearance of Utsuri with Changing Light Angle
Varying Appearance of Utsuri with Changing Light Angle

Moving it through the light illustrates all kinds of depth and beauty in the ji, as the utsuri effects reveal themselves as dark and light patterns and colors shift like a kaleidoscope. Photos cannot tell the full story of a blade like this, as the dynamic nature requires two eyes and physical movement through the light. Parts of the hamon as well are done more like the oldest Nagamitsu work, with middle and larger size choji midare. The jihada appears almost flawless, though there are a couple of openings inside the bohi. This happens as bohi cuts into the core steel of swords which is more coarsely forged.

1987 and 1952 Torokusho
1987 and 1952 Torokusho

This blade has a torokusho from Showa 26 that illustrates it was most likely in a daimyo collection at the time. Showa 26 is 1952, and this is the first year of registration for swords under the licensing regime. Daimyo blades were used in order to start the process at this time, and this torokusho has a very low serial number of 2363. The NBTHK Juyo Token description also states that the blade had an older attribution that was being agreed with, this was likely an old sayagaki. The hints of what this could have been are on the copy of the old torokusho, as it records what was on the nakago at the time. It reads Nagamitsu on one side and Koson (kao) on the other. So it seems that this sword had an attribution, and either a sayagaki or origami from Honami Koson, the famous polisher and appraiser from the first part of the 1900s.

By the time the sword got to Juyo this shumei was removed. Possibly it wore away but I think that it was removed during the papering process because the NBTHK wanted to place it to Sakon Shogen Nagamitsu. The irony of course is that now there is no difference in these attributions. Possibly because the owner was made to remove the existing shumei, he asked Dr. Honma to replace it with a kinzogan mei after it passed Juyo.

Because a new kinzoganmei like this alters the state of the nakago, the sword has to go in for a new torokusho and the Juyo papers also get updated and replaced with a reissued oshigata and the old one is turned in. I only know that it was mumei because the books for each session published both oshigata for the sword. Overall this gives us a bit more insight about the authentication process and thankfully the old preserved torokusho copy gives us insight into the history of this blade. 99% of the time this kind of information is lost today.

Any blade by Nagamitsu is a treasure handed down to us from feudal Japan. To own something like this is a coup, though many Nagamitsu exist, not many people get a chance to own one. This one is among my favorites I have seen by the smith, and it's the first time I've had one for my site. It is a real Bizen masterpiece, showing restraint, subtlety and exuberance in balance. A blade of this quality is worthy of submission to Tokubetsu Juyo and I think this blade can contend in 2020. If you want a blade that will never tire you by one of the best smiths of all time, I can't recommend this one enough.

Ko-Osafune Nagamitsu Katana OshigataKo-Osafune Nagamitsu Katana Origami

Juyo Token Katana

Designated at the 21st jūyō shinsa, March 1, 1973

Katana, Mumei, Nagamitsu


shinogi-zukuri, iori-mune, normal mihaba and kasane, despite of the ō-suriage a deep koshizori, chū-kissaki


dense ko-itame with ji-nie and a midare-utsuri


overall rather densely arranged chōji in ko-nie-deki that is mixed with gunome, ashi, yō, and kinsuji


gently undulating notare with a ko-maru-kaeri


on the omote side a bōhi and the characters Hachiman Daibosatsu and below traces of a bonji and a rendai in the upper part of the nakago; on the ura side a bōhi and a kurikara


ō-suriage, kirijiri, katte-sagari yasurime, three mekugi-ana


It is said that Nagamitsu (⻑光) was the son of Mitsutada (光忠) and the smith who bore the honorary title Sakon Shōgen is traditionally regarded as the second generation Nagamitsu. In chronological terms, Nagamitsu blades signed with the Sakon Shōgen title appear to date later than the others and they usually show a more calm ha composed of smaller elements. The question if these works go back to the latest years of Nagamitsu or indeed to a second generation needs further study but we can clearly distinguish two different Nagamitsu workmanships. We are in agreement with the period attribution and it has to be mentioned that such horimono are occasionally seen with Shōgen Nagamitsu and with Kagemitsu (景光).

Ko-Osafune Nagamitsu Katana Sayagaki


This sword bears two sayagaki. The front side is by Dr. Honma Junji, the co-founder of the NBTHK.

  1. 備州⻑船左近将監⻑光
    Bizen no Kuni Sakon Shogen Nagamitsu
  2. ⼤磨上象嵌⼊
    Ō-suriage zōgan hairi.
    Shortened and gold inlay added.
  3. 刃⻑⼆尺四⼨⼀分
    Hachō ni-shaku yon-sun ichi-bu
    Blade length 73.0 cm
  4. 昭和甲子。。。
    Showa 59 (1984)
    Date and Signature of Kunzan (Dr. Honma)

On the back is an extensive (and a lot longer than normal) sayagaki by Tanobe Michihiro, the retired former head researcher of the NBTHK.

  1. ⼤磨上無銘ノ茎ニ薫⼭先師ノ将監⻑光ト鑒スル旨ノ⾦象嵌有之
    Ō-suriage mumei no nakago ni Kunzan senshi no Shōgen Nagamitsu to kan-suru mune no kinzōgan kore ari
    Greatly shortened and unsigned nakago, to which my former teacher Kunzan had his attribution to Shōgen Nagamitsu inlaid via kinzōgan.
  2. 而刃長弐尺四寸一分也
    Shikamo hachō ni-shaku yon-sun ichi-bu nari.
    The length of the blade is 73.0 cm.
  3. 身幅尋常今ナホ反高ク丁子乱ニ小互乃目ヲ交ヘシ乱ヲ焼キ出入アレド丁子ノ房ガ小模様デ間ノ詰マル状ヲ呈シ乱映ノ立ツ精妙ナル肌合ト相俟ツテ正ニ長光中後期正應・永仁頃ノ左近将監ヲ冠スル同工在銘作ニ結バレル者有之
    Mihaba jinjō ima nao sori takaku chōji-midare ni ko-gunome o majieshi midare o yaki deiri aredo chōji no fusa ga ko-moyō de aida no tsumaru jō o tei-shi midare-utsuri no tatsu seimyō nary hada-ai to aimatte masa ni Nagamitsu chū-kōki Shōō, Einin goro no Sakon Shōgen o kan-suru dōkō zaimei saku ni musubareru mono kore ari.
    It is of a normal mihaba and still has a deep sori. The hardening is a chōji-midare with noticeable ups and downs that is mixed with ko-gunome. The chōji tassels are are small dimensioned and the elements of the hamon are densely arranged. With the midare-utsuri and the exquisite hada, we truly recognize the style of Nagamitsu from his middle and later active period (from the beginning of Shōō 1288 to the end of Einin 1299). The features of this sword tie it to extant signed works from this period that have Sakon Shōgen in the mei.
  4. 出来ノ良サニ加ヘ孕龍ノ彫モ味ワイ深矣
    Deki no yosa ni kae harami-ryū no hori mo ajiwai fukai.
    Apart from the excellent deki, the blade features a very tastefully executed pregnant dragon engraving.
  5. 第二十一回重要刀剣指定于時戊戌極月後學探山識「花押」
    Dai nijūikkai jūyō-tōken shitei Koretoki tsuchinoe-inu gokugetsu Kōgaku Tanzan shirusu + kaō
    Written by the younger scholar Tanzan (pen name of Tanobe Michihiro) in December in the year of the dog of this era (2018) + kaō