Ko-Osafune Norimitsu KatanaKo-Osafune Norimitsu

periodKamakura (ca. 1303)
designationNBTHK Juyo Token
nakagoo-suriage, kinzogan mei "Norimitsu", ura "Hon-na" (Honami Kokan's kao).
nagasa67.2 cm
sori1.5 cm
motohaba2.7 cm
sakihaba1.7 cm
kissaki2.85 cm
nakago nagasa21.5 cm
nakago sorislight

Ko-Osafune Norimitsu is a smith of the middle to late Kamakura period, and his work is only rarely found. He is a student of the great Bizen grandmaster Nagamitsu, a name familiar to all sword collectors. Fujishiro puts his working period at 1303 and rates him Jo-saku. This rating carrys a lot of weight because his contemporaries are smiths like Kagemitsu, and Nagamitsu in the Bizen school, and in this period many of the Kamakura greats such as Rai Kunitoshi, Shintogo Kunimitsu, Norishige, and Yukimitsu are all active. It is simply one of the shining moments of sword manufacture.

His name is taken up later on by the Muromachi period smiths, and because Ko-Osafune Norimitsu's work is so rare, it is easy to confuse the work by name, though not by quality and construction. His work is very close to Nagamitsu in style.

The Osafune smiths are founded by Mitsutada, and his son Nagamitsu ran a large workshop and his work is frequently found. In many cases it is teamwork under the supervision of the master. Fujishiro writes:

Among the old famous swords which exist today, there is no swordsmith who has left behind a number of works which surpass those of Nagamitsu. He was of the true lineage of the Osafune Kaji, and confronting the warfare of Bun'ei and Koan, there were probably many opportunities for yet another level of vigor. It is extremely difficult for one person to make a sword all by himself, and it requires the cooperative efforts of several people. The son and the father, the younger brother and the older brother, the pupil and the teacher, each helps with the manufacture through their respective assistance.

Therefore, even though the product has "Nagamitsu" on it, it is not something that was made by one person named Nagamitsu, but it can be said to be a cooperative work made through the joint efforts of many people in one extended family. Along with the excellence or inferiority of the technology of all the co-workers exerting much influence on the product, the swordsmith of the legitimate lineage bore the responsibility himself for the efforts outside of their own technology. Both those with many works, such as Nagamitsu, Kagemitsu and Kanemitsu, and those whose works were few, such as Sanenaga, Kagemasa and Yoshimitsu, and the swordsmiths whose work we do not see even though the number is great and who left behind only their names in the Meikan, were all based on this.

To paraphrase, Fujishiro is pointing out that the works of Nagamitsu in number far outstrip his ability in terms of time to produce all of them, while we know of all of these smiths in his extended family with names but comparitively few works bearing their own signature. By this he surmises that Nagamitsu work must be carried out by a family of smiths under the supervision and direction of the grandmaster who's signature appears on the blade. When there is a variation in quality it is likely due to a more senior or junior group producing a particular work, and in the likelihood of the topmost quality these would be thought to be work done directly by the hands of the master with his top students assisting.

Norimitsu was more likely most active in these teams, as were the other students, which kept production in his own name low and rare.

Kagemitsu was the son of Nagamitsu and carried the lineage forward. Kagemasa is the younger brother of Kagemitsu, and possibly the age difference is great because he would appear to be the student of Kagemitsu based on his name. The peers and fellow students of Kagemitsu were Sanenaga (probably eldest), Sanemitsu, Nagachika, Kagemasa, Nagamune, Nagamoto, Norimitsu. Other smiths involved in the shop of various ages include Yoshimitsu, Mitsukane, Moritada, Morishige, Toshimitsu, and Chikakage. All carry excellent reputations as one would expect from the wide renown and fame of Nagamitsu during his own time and in the present.

Juyo Token Ko-Osafune Norimitsu Katana

Juyo Token Ko-Osafune Norimitsu Katana

The sword itself is a beautiful and healthy work, featuring fine mokume jihada and many small dark chikei. The hamon in an undulating choji with ashi and yo is very typical of the school of Nagamitsu from this time. The hamon is very bright and as can be seen in the photos, is very beautiful. Utsuri appears throughout the sword and has been captured in some of the photos, which is usually a difficult task to achieve.

Norimitsu’s relationship to Nagamitsu is conspicuous in this sword. One of the most striking similarities is in the choji hamon which rises high into the ji with large well formed lobes, but the boldness and size of the choji pattern slowly changes passing into the monouchi becoming a smaller gunome midare based on suguha or even pure sugu. The nioiguchi also becomes a bit wider and forms small togari rising as whisps into the ji. This characteristic of the hamon softening in the monouchi is evident on many Nagamitsu works with one such example in the Tokyo National Museum, as well several Juyo Bijutsuhin. Works by Sanenaga and Kagemitsu also exhibit this feature.

While Nagamitsu boshi are commonly regarded to be sansaku, he also worked in midarekomi. The boshi on this Norimitsu is midarekomi on both sides, but the sashi ura is noticeably more expressive of gunome with long ashi in contrast to the sashi omote that is softer and has a bit of sansaku influence in the overall shape. It is also placed deeper in the kissaki which is a departure from Nagamitsu’s boshi which tend to follow more closely to the hasaki.

At a glance it is a work of the late Kamakura period, featuring the elegant tapering sugata typical of the time. The work in the hamon is extremely close in the hamon but is likely ruled work of Norimitsu by considering the boshi which does not entirely embrace the sansaku type that would bring the decision down to Nagamitsu, Kagemitsu or Sanenaga.

As mentioned above, this sword carries an attribution by Honami Kokan, who was active roughly between 1790 and 1850 and was the 10th generation head of the Koji line. He was actually born the son of the 7th master of the main line and adopted into the Koji line. The kinzogan is beautifully done, and the NBTHK affirmed the judgement in passing this sword to the prestigious Juyo Token level. The attribution in kinzogan by the Honami masters are held in high regard.

There are some burnishing marks on the sword as this is an item in old polish, they can be seen on the mune and near the ha. I think it should be possible to have those under the yakiba to be addressed by a polisher in a fairly straight forward manner but it is a matter for a polisher to comment.

I can certainly recommend this gorgeous and rare work of the Ko-Osafune school for collectors at any level, particularly those interested in Bizen.

Ko-Osafune Norimitsu Katana Oshigata

Juyo Token Katana

Appointed on the October 9th of 2003

Katana, Kinzoganmei, Norimitsu (Osafune, Jidai Kamakurai Sueki), Hona (Kao, Kokan)


Shinogi-zukuri, iori-mune, and normal mihaba. There is a slight tapering from moto-haba to saki-haba and shallow sori with slight koshi-zori. Chu-kissaki.


Overall, it has a well forged ko-itame hada mixed with mokume. There are some tiny ji-nie, fine chikei and developing midare-utsuri.


Gunome mixed with choji with round kashira, as well as some togari-ba, which are forming beautiful midare with lots of ashi and yo inside. There are ko-nie with more nioi and a bit of kin-suji and suna-nagashi.


Midare-komi with a slight hook forming a ko-maru, and fine haki-kake on the tip.


O-suriage with a shallow kuri-jiri where the nakago end is relatively flat. The yasuri-me (i.e., file marks) on the top half of the omote side are kiri, whereas the file marks on the bottom half are suji-kai. On the ura-side, the file marks are katte-sagari. There are two mekugiana. On the sashi-omote side, the mei “Norimitsu” is carved in hira-ji below the 1st mekugi hole. On the ura side, there is a gold zogan kiwame mei by “Hona[mi] (kao) (Kokan)” also below the 1st mekugi hole.


Generally, Osafune Norimitsu is understood as a famous smith who worked during the mid Muromachi period or so: Eikyo (1429 - 1441) era in Bizen province. However, in the Nihonto Meikan, there is a reference on Norimitsu, a student of Nagamitsu who worked in the late Kamakura period. It designates the particular Norimitsu as the shodai (i.e., 1st generation). Amongst the existing swords made by the Shodai Norimitsu, there is a tanto with a Kagen 3rd year (1305) date inscription. This tanto blade exhibits kata-ochi gunome hamon that resembles a typical work of Kagemitsu. Other than that, there are few existing blades confirmed to have been made by the Shodai Norimitsu.

This particular o-suriage blade was appraised and determined by the 8th successor of the chief of the Honami family, Kokan, as the authentic work of Norimitsu of the late Kamakura period, and thus received a kinzogan mei by him. It has a well grained koitame-hada mixed with mokume. There are some tiny ji-nie, fine chikei and developing midare-utsuri. Its hamon shows gunome mixed with choji with round kashira, as well as togari-ba, which are forming beautiful midare with lots of ashi and yo inside. There are ko-nie with more nioi and a bit of kin-suji and sunagashi inside. These activities remind us of works of the main line of Osafune smiths, especially Nagamitsu. The connoisseurship of Honami Kokan, who attributed this blade to a work of Norimitsu, was definitely just and appropriate. This is indeed a wonderful work attributed to Norimitsu.