Niji Kunitoshi KatanaNiji Kunitoshi

designationJuyo Token
periodMiddle Kamakura
nakagoO-suriage mumei, 1 mekugiana
nagasa68.75 cm
sori1.55 cm
motohaba2.8 cm
sakihaba2.1 cm

Niji Kunitoshi is a luminary smith of the koto era Yamashiro Rai school era, working in the Koan period. He is listed in Fujishiro as Sai-jo saku, for highest quality of craftsmanship in his period and school, and he is listed in the Toko Taikan at 2,000 man yen. This makes him one of the most highly rated smiths, falling somewhere between Sadamune and Kotetsu. He left behind a comparatively large number of works, leading to a consideration that there may have been daimei and daisaku works by his students.

His father was the similarly talented Rai Kuniyuki, who is the first smith in the Rai school with extant works. The Rai school was founded by the legendary Rai Kuniyoshi, who is supposed to have been a main from Korea, but no authentic works exist to prove this theory. Any swords found signed Rai Kuniyoshi should be examined with this fact in mind.

In theory, Rai Kunitoshi has two incarnations, the first in which he signed with a two character (niji) mei, and the second where he signed with a three character (sanji) mei.

There is a theory that Niji and Sanji were different smiths (possibly brothers), but the theory that is gaining acceptance is that the smith known as Niji Kunitoshi ushered in a renaissance in sword making by changing his style halfway through his career.

Along with the style change, comes a change in signature, the characters gain in size, and the Rai character precedes his new mei. This theory has been given credence lately by discoveries of works signed sanji mei but with niji characteristics. In particular, a kodachi has been found signed like this which shows the characteristic choji midare of Niji Kunitoshi.

When it comes to dated works, there is one extant work of Niji Kunitoshi with the date of production (1278), and another with the date of 1286. The production dates of Rai Kunitoshi have been confirmed between the Sho-o and Genkyo eras (1288 - 1319). This, the total active term of Niji Kunitoshi and Rai Kunitoshi counts for 41 years, a reasonable work span for a long lived smith.

There is also an extant work of Rai Kunitoshi with the date of Showa 4 (1315) and the age of 75 (Juyo Bunkazai). Counting backwards from this age, the tachi by Niji Kunitoshi with the date of Ko-an 1 (1278) corresponds to his work at the age of 38. Again, this indicates that it is entirely plausible that Niji Kunitoshi and Rai Kunitoshi are the same person.

Like many theories in the Nihonto world, much of this issue boils down to an opinion (often emotional!) and there will surely be supporters of both theories going into the future.

Of his work, there are 163 Juyo Token, with 47 of them being the Niji variety. Of the 163, there are 17 Tokubetsu Juyo Token (and the like), 9 of which are of the Niji variety. As these collectively likely represent a number close to the total known output of this smith, it is clear that the Niji variety are the more rare. Furthermore, as 1 in 5 of the Niji variety are higher than Juyo Token (a very high ratio), they can be seen as considered more important than the Sanji variety which have a ratio of about 1 in 15 being higher than Juyo.

Niji Kunitoshi is known for a majestic, beautiful, and active choji gunome hamon, replete with ashi and yo. This hamon is considered to be "imported" from the incredible Bizen works of this time period. His kitae features soft itame or ko-itame. There are often ji-nie, and sometimes these will form utsuri in his works. This style is inherited from his father, Kuniyuki, and his work is generally considered to be grander and more beautiful than that of his father.

It is not outrageous to imagine that great smiths of all eras may be interested in experimentation and improvements of methods and results. Keeping this in mind, it is not a big leap to consider that with what we know, a smith like Niji Kunitoshi may be one such example of this happening. This may explain the revolutionary change in style, where the robust and wide sugata and choji midare hamon transforms into the slender, tapering sugata and suguba hamon of Rai Kunitoshi.

Niji Kunitoshi Reference

This example oshigata is one of two known dated Niji Kunitoshi works, so is very precious for this fact. It resides in the Tokyo National Museum, and is signed Kunitoshi, Koan Gannen Junigatsu Hi (A day in the 12th month of 1278), 77.9 cm. The image on the left is a scan of the Juyo Token Niji Kunitoshi from this listing.

sword picture

It is particularly interesting because of the similarities in boshi, which are not entirely evident from the Juyo Token Oshigata, but are more evident to the eye.

Juyo Token Niji Kunitoshi

This is a Juyo Token of very high caliber. It is a sword with a spectacular hamon and wonderful jigane, which Tanobe sensei of the NBTHK has called a reference work for the study of this smith. The health of the piece is more commonly found on works of the Shinshinto period, so it has come through to this day and age in fantastic condition.

While the NBTHK in their dissertation on the sword draws attention to the skillful hamon, the boshi is also something very special in this sword. I was able to capture the texture and complexity in the slideshow photographs.

This sword was found, rusty and in gunto mounts by Robert Benson. At the time I bought it, he felt it to be the second best sword in his collection.

Before polishing, there were many battle scars on the sword, testifying to its robust nature and faithful service: it fought and never bent or broke in battle. Many of the scars were repaired by the polisher by gently tapping them out with a hammer. A scar in steel is made by displacing the metal rather than removing it, and the soft steel of the mune and ji can be parted in this way by the hard steel of another sword's ha. By tapping, the material can be made to flow back into the scar and "heal" it. Often times battle scars are left in place in a sword as badges of honor, testifying to the reliable service of the blade.

Two are still visible in this sword, one on the ura ji (pictured in the slideshow), and one on the mune. Keeping in mind that this sword was made around 1280, and was taken to war as late as WWII, it has proudly served its owners in battle over a career spanning over 650 years. That it has survived intact is nearly miraculous, and testifies to the skill of its maker.

Not mentioned in any of the descriptions is faint ji-utsuri formed by ji nie, more prominent on one side of the sword than the other. Also interesting is the visible polished area above the patina in the nakago. This is evidence that as late as WWII, there was active shortening of koto period swords for personal tastes or to fit into period koshirae.

Niji Kunitoshi Katana Oshigata

Juyo Token Katana

Appointed on Oct 11, 2001 - Session 47

Katana, Mumei, Den Niji Kunitoshi

Keijo (form)

Shinogi Tsukuri, Ihori mune, Mihaba and kasane are both normal, with little difference in the width of motosaki, rather shallow sori, lengthened naka kissaki.


Choji at its base, mixed with gunome, togariba, and suguha in some places. In general, deiri is unnoticeable, with well displayed ashi(foot) and ha(leaf), deep nioi, thick nie, kinsuji and sunagashi. There is a little muneyaki, nioiguchi is bright and silvery.


Itame moku majiri, fine kitae hada (grain), ji nie mijin (very fine) and light nie can be seen.


Midarekomi, komaru on the obverse side and togari (sharpened) on the reverse side, both hakikake.


Oosuriage, sakigiri, yasurimegiri, 1 mekugiana, mumei.


Kunitoshi is said to be a child of Rai Kuniyuki. There are so called Niji Kunitoshi that has no "Rai" and Rai Kunitoshi, sanji. Niji Kunitoshi and Rai Kunitoshi can be the same person considering the years those existing swords were made. But you can find a certain difference in the manners they were created therefore it is possible to distinguish them. There are two theories, one saying they are the same person and the other saying they are different persons, but it is still hard to tell which is correct.

This sword is O-suriage mumei but has nie shown on itame, choji based, rather spectacular midare yakiba, and well displayed nie, with muneyaki. These are characteristics of Niji Kunitoshi. The legend is credible and it shows excellent work.

Niji Kunitoshi Katana Sayagaki

Tanobe Sensei Sayagaki

  1. 重要刀剣指定品
    Juyo Token Shitei Hin
    Important Sword Designated Article
  2. 城州二字國俊
    Joshu Niji Kunitoshi
  3. 但大磨上無銘也
    Tadashi o-suriage mumei nari
    Although shortened and unsigned
  4. 同工ノ一典型ヲ示ス佳品而
    doukou no ichi tenkei wo shime su kahin nishite.
    it is an excellent reference work by Niji Kunitoshi.
  5. 地刃健体ナルモこのマシ
    Jiba kentai narumo konoma shi
    The jiba is healthy and also pleasant.
  6. 珍々重々
    Chin chin, cho cho
    It is held in great esteem.
  7. 刃長貳尺ニ寸七分五厘有之
    Hacho ni shaku ni sun nana bu ari kore
    The cutting edge length is 2 shaku 2 sun 7 bu
  8. 平成辛巳暦霜月上浣
    Heisei kanotomi reki shimo tsuki jokan.
    November 2001 (year of the snake), first ten days of the month.
  9. 邉探山鑒誌(花押)
    Hen Tanzan Kan Shirusu (kao)
    Tanzan appraised and ascribed (seal).