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The Koto Bingo Mihara School

By Allan H. Pressley

The Mihara School started in Bingo Province around the Shochu era (1324 - 1326), according to Yamanaka, which contradicts other information, and lasted through into the Shinto period. All Yamanaka says about the Shinto smiths, in Volume 4, issue 11, page 12 of Nihonto Newsletter, is that "Descendants of the late Mihara School and of the Goami School made a few blades." Bingo is on the Sanyodo Highway, on the south side of the western portion of Honshu, the main island of Japan. It faces the inland sea, beside Bitchu province.

The work of the school is in the Yamato tradition, and is divided into the Ko Mihara, Chu Mihara, and Sue Mihara. Interestingly the man believed to be the founder of the school, Masaiye, (according to Yamanaka), is believed to have come from either Bitchu or Bizen province. However, he may have originated in Yamato province, since the school is in the Yamato tradition, and passed through the Bizen school provinces (Bitchu has a Bizen tradition) on his way west along the Sanyodo to Bingo. "Token to Rekishi" in #545, page 54, says the founder of the school was Masaiye, from the late Kamakura period (1278-1333). In any case, Masa remained a common element in the Mihara smiths names, and all of the smiths Hawley lists in his "Japanese Sword smith Groups" all begin with Masa. One of our swords here tonight is by Masaoku. Yamanaka mentions that there were also the Ichijo, Shimbo* and Tomo schools, without saying if they were Mihara schools, or other schools. Later he implies that the Tomo school is a sub school of the Mihara group, but it is not clear.

Ko Mihara

The work made from the end of the Kamakura period or about 1278 until the Oei period (1394), are classed as Ko Mihara. There are few remaining examples of these blades.

The characteristics of Ko Mihara according to Yamanaka in Nihonto Newsletter are;

Shape - Shape of the mid Kamakura period (Torizori with fumbari and tapering narrow towards the kissaki) with high shinogi and hiraniku.

Hamon - Narrow hamon and in nie, also chu suguha in nioi and with ko midare mixed in with some nie within the nioi. There will be uchinoke, hakikake and nijuba in many swords. Also some that resemble Yamato Tegai.

Boshi - The boshi will be the continuation of the hamon with ko maru at the tip, then dropping abruptly so that the tip will be made in togari. I interpret this to mean the boshi shown in figure 2. In the 1975 Bulletin of the JSS/US (which also includes an article on Kaneiye tsuba by Arnold Frenzel), Yamanaka has an article on Inaka smith or smiths who worked outside the 5 traditions. In it he shows two types of Ko Mihara boshi. They are shown in figures 2 and 3. Figure 2 is the taki-no-otoshi or waterfall boshi and figure 3 is the tora-ano-o or tiger tail boshi. If you look at actual examples of swords show in various oshigata, they seem to be shorter and more irregular than those shown in the figures. He also says that certain works will have haki kake boshi. He also shows a short abrupt kaeri, as shown in figure 1. He says Mihara is very easy to tell by the kaeri.

Jitetsu - Mokume hada with masame hada mixed in. There will be small sumitetsu in most works. In the 1975 bulletin Yamanaka expounds on this. He says the Mihara blades are hada ga tetsu, meaning the skin stands up. He says it's hard to explain without seeing the blades, but it give you the feeling of rough texture in the blade. He does not comment on utsuri in the Nihonto Newsletter, but in the JSS/US Newsletter 5/6-1980 page 21, he says that Bingo Mihara has shirake utsuri or fuzzy whitish utsuri. From somewhere, I have the impression that the masame grain is next to the hamon, but I can't find a reference in print, except for some specific examples.

Nakago - Slightly short length made a little broad in tanagobara style with tip in either Kengyo or ha agari Kuri jiri and with katte sagari file marks.

Yamanaka says tanto are average length and other characteristics about the same as longer blades.

The terse description in Teiryo Yoji agrees with Yamanaka in its points. Hawley, in his "Japanese Sword smith Groups", says Ko Mihara has mokume-masame, suguha/ashi, small gunome/suguha mixed and nie; and 1325 to 1400 as the time period.

Fukunaga, in his "Nihoto Kantei Hitsu Kei", on page 247, shows the kantei points of a Ko Mihara blade. Since it is all in Japanese, I can glean only a few points from the book. It shows a very long kaeri, komaru boshi, suguha hamon with small ashi, and yo, small gunome in the hamon, dark spots (sumitetsu) in the ji, and presumably, a high or wide shinogi.

Robinson, in his "Primer of Japanese Sword - Blades", says that early Mihara blades are 1325 - 1400 time period, and are mostly long swords with itame, suguha, and sometimes with ashi. There are several actual examples in various literatures that can be examined, as follows:

Token Bijutsu #42, page 18, Bishu Masaiye. This sword pretty much follows Yamanaka's description for a Ko Mihara and it has a boshi like figure 2. Interestingly, some of the students said it was a Bitchu Aoe school blade. They do say that in addition to the normal style, Mihara smiths also work under strong Aoe influence. They also say the jitetsu of both schools is more or less in chirimen style. Chirimen hada is supposed to look like crepe silk. This is very interesting because it is the first time I have read that Ko Mihara has the chirimen hada of the Aoe school.

Token Bijutsu #12, page 16, Bishu no Ju Masaiye. This sword has itame mixed with mokume rather than masame mixed with mokume. It has a boshi in which the long kaeri is slightly curved, as seen in figure 4.

One thing to remember, if you see a sword with a signature starting with Bishu, it doesn't necessarily mean it's a Bizen sword. It could also be Bitchu or Bingo.

This sword is a Nambokucho blade. Only a few of the students called it Ko Mihara, most of them considered it an Aoe blade. They say: "Aoe's steel texture is indeed fine and stands out clearly, it, however, seldom contains as obvious mokume as what is showing clearly in this example.

Token To Rekishi #544 and 545, kantei section - Ko Mihara Masahiro. This sword is a ko-dachi. They say one blade exists with active sugu chogi similar to Bizen Osafune Chikakage. Main I.D. point on subject sword is well-refined Bizen style mokume, (which is somewhat different than the previous comments) and along the ha very strongly flowing masame. "From ancient times a strong feature of Mihara blades has been their wake no kitae or divided kitae." The sword has a shot kaeri, shirake utsuri, a high shinogi and a suguha hamon with tight nioi guchi with ko nie, and is slightly hotsure. It has kiri yasurimei on the nakago.

Token to Rekishi #559 front. Ko Mihara Masahiro. This blade is also a ko-dachi, but not the same one. This blade has saki zori, which seems unusual for a blade in this time period. It has longish kissaki, mokume mixed with flowing masame near the ha, extremely well refined shirake utsuri, and a completely nioi based suguha with nie in the habuchi. The nioi guchi is tight, bright, and clear. It has a suguha boshi, brushed point and ko maru with a very elegant kaeri. Since it's a photograph of a blade, rather than a hand drawn oshigata, you can't tell if it's a long kaeri.

Compton Catalog #28 Ko Mihara Masakiyo, This blade is a hira-zukuri tanto with wide section and shallow curvature typical of Nambokucho period shape, dated Oan period (1368). It has a slightly wavy suguha temper line mixed with ko notare in places made in ko nie. It has fine and dense ko itame, which Ogawa says is typical of the Mihara school, which somewhat contradicts Yamanaka and the other authorities. This example has a short kaeri on the boshi. The nakago has a kuri jiri end with kiri file marks.

The first 4 examples compare reasonably well with the ideal however, the tanto in the fifth example seems to be completely different, and I certainly wouldn't pick it as a Ko Mihara in a Kantei session. It is normal, when you compare actual examples against the ideal characteristics to find that they don't compare well.

Kataoka, in "Nihonto Zuikan - Koto-hen", shows Bingo swords on pages 900 to 920, through the Koto period. There are 17 swords clearly listed as Ko Mihara, and the great majority of these swords have a suguha hamon, a long kaeri, and a chu or slightly extended boshi. Some have the short broad nakago, but not all.

Chu Mihara

Yamanaka says that at the time of the Oei period (1394) a number of smiths moved to various parts of the province and set up their own groups known as Ashida, Tomo (note here he calls Tomo a Mihara sub school, where earlier he implies that it is a separate Bingo province school), Kinashi, Shimbo* (ditto) and Kai. He says that Chu Mihara work is very rare, but it will be about the same as Ko Mihara though slightly inferior in workmanship. He lists the time period for Chu Mihara from Oei (1394) to Eikyo (1429). Hawley lists Chu Mihara as ko-mokume-masame, medium suguha and ko-midare, and 1350 to 1450 as the time period. Robinson does not list a Chu Mihara school, only an early, and a later, which he says lasted from 1350 to 1450.

Sue Mihara

Yamanaka gives the characteristics of Sue Mihara blades as follows:

Shape - Style and shape of Sengoku period (approx 1460 to 1600) with the sori made a little shallow and more graceful than other works of this period.

Hamon - Narrow Yakiba in chu suguha (which seems inconsistent), the edge of hamon will be very distinct and there will be little to see within the hamon. In certain work there will be midare and a very small gunome. In addition, there will be midare as seen in Bizen and Mino work from the same period.

Boshi - Ko maru with deep kaeri with waterfall and tiger tail styles as is Ko Mihara. He says that tiger tail kaeri is known as the Mihara kaeri and is seen most on Sue Mihara work.

Jitetsu - Ko mokume hada stands out very distinctly. Sumitetsu will be encased in the ko mokume hada in very small size.

Nakago - Made short with the tip made broad in Kurijiri. Also, tanagobara with tip made in Kengyo. Kiri file marks.

Tanto - Made in Chukan zori (no sori at all - mune is straight). Some with slight saki zori. In addition there will be shobu zukuri, unokubi zukuri and moroha. Some tanto will have a yahazu midare hamon.

Notes: Those hamon worked in chu suguha will be quite often mistaken for Hizen Tadayoshi of Shinto period. In the Shinto blades, if attention is paid to the boshi and its Kaeri, then the difference should be apparent. The hamon worked in midare of the Bizen style, the nioi is very distinct at the hamon edge and there will be very little nioi shimi within the hamon. The hamon made in the Mino style will have the peak of the midare from the start to the tip. (real Mino is never uniform).

Hawley shows Mokume, gunome, open midare, medium suguba - ko midare, as characteristics of Sue Mihara, and lists them as lasting from 1350 to 1500.

Robinson says that later Mihara (he only divides them into 2 groups, not 3) was from 1350 to 1450. He says they made mostly wakizashi and tanto, with itame, and suguha or crumbling suguha.

Following is a discussion of the 4 swords we have as actual examples.

Sword #1

This sword received a 70 point paper at the 1989 shinsa and was dated at 1530. It is signed Bingo Mihara Ju Nin Masaoku Saku.

It is an ubu wakizashi, mounted in 1914 pattern Naval officer's mounts. There appears to be a mon engraved on the hilt, of the tsuka or ivy, which was used by a number of families in this version. The mounting is quite interesting, as it was a presentation sword to Gakucho from Nagai and Wahara and is engraved "One sword to conquer a 1000 warriors."

Shape - Tori zori that almost appears to have a slight koshi zori, a fair amount of taper, and a longish kissaki. It is my personal opinion that is one of the finest shaped wakizashi I have ever seen. This sword has not been thinned down much from polishing it was thin to start with. It has a high shinogi, but a standard to narrow shinogi ji and a high mune.

Hamon - This sword has a very quiet and beautiful suguha with a tight nioi guchi. It has fine nie in the nioi guchi. The hamon follows the shape and reminds one of a good Hizen blade.

Boshi - Suguha with a ko maru and what might be a fairly long kaeri, but it's hard to tell. The boshi is quite well done and has a lot of sprinkled nie.

Jitetsu - Fairly fine mokume. There doesn't appear to be any masame. There is a faint utsuri on the omote side and strong utsuri on the ura side. There are 4 or 5 patches of shintetsu showing on the ura side, which breaks up the utsuri.

Nakago - The nakago has a fair amount of sori which follows the sori of the blade. It has kiri yasurime and a fair amount of taper ending in a small hagari kuri jiri. The signature is compressed together.

General Comments - This sword looks very much like the one shown on page 910 of Kataoka's Koto hen, which is signed the same way, but the signature doesn't compare. Fukunaga, on page 465 shows two Bingo Mihara ju nin Masaoku signatures, both from the swords in Kataoka, and the lower one compares well with this sword. Hawley shows 4 Bingo Mihara Masaoku's from 1504 to 1573, 3 of which were Kai Mihara. This sword is serene and beautiful, and certainly expresses the stillness that a suguha hamon is supposed to express.

When I look this sword, it almost seems to me that Hizen Tadayoshi got his inspiration for his school characteristics from the Bingo Mihara school, rather than the Yamashiro school.


Length: 19 3/8", sori: 13/32" (2% curvature)

Width at motohaba: 1 5/32", width at sakihaba: 23/32 moto Kasane 0.240"

Sword #2

This sword received a 70 point paper at the 1989 shinsa and was attributed to the Bingo Kai Mihara school and dated at 1570. It is an o-suriage katana in gunto mounts with a Goto mon on the hilt. It was acquired by its first American owner in Formosa at the end of the war. It had a surrender tag marked colonel Goto of the adjutants section and mumei Enju. It has a field grade officers sword knot.

Shape - Medium koshi zori with narrowing in the monouchi, and a feeling of saki zori. The sword has a high shinogi, the shinogi ji seems to be normal to me, although one whose opinion I respect, calls it wide. The sword has a chu Kissaki. It has a normal height iori mune.

Hamon - Suguha with a variable width nioi guchi, almost crumbled in places. There is ko nie in the nioi guchi, kinsugi, shallow ashi, nioi kuzure (the reverse of ashi). The hamon has quite a lot of activity. There is nijuba and uchinoke on the omote. The hamon could also be considered having hotsure in places.

Boshi - Suguha with ko maru and a long kaeri on both sides.

Jitetsu - Omote: mokume and itame rather open, with some masame, fine ji nie, strong utsuri. Ura: tighter itame with some mokume, fine ji nie, utsuri. The hada on this sword is very nice.

Nakago - O-suriage, kirijiri, kate sagari yasurime in lower 2/3, three mekugi-ana.


Length: 26 5/8", sori: 23/32 (2.7% curvature) width at mothball: 1 1/8", width at sakihaba: 3/8"

Moto kasane: 0.229" nakago length: 8 3/16"

Sword #3

This sword received a 60 point paper at the 1989 shinsa and was attributed to the Bingo Kai Mihara group, and was dated at 1570. It is an O-suriage wakizashi mounted in buke zukuri mounts.

Length: 18 3/8" sori: 1/2" (2.7% curvature) width at motohaba: 1", width at sakihaba: 3/8", motokasane: 0.220", nakago length: 5 3/8"

Shape - Strong koshi zori with a high amount of sori, chu kissaki, high shinogi, high mune, and a fair amount of taper. This blade is very thin, but appears to have been shortened lately, since there is no thinning of the blade past the nakago, and the nakago patina is not very dark.

Hamon - Chu suguha with considerable activity in uchinoke, hotsure and kinsugi. The nioi guchi is variable in width because of all this activity. There is nijuba on the ura at the yokote. Note the crumbled or hotsure section which goes to a tight nioi guchi, starting from the hamachi.

Boshi - Because of the state of polish on this sword, it is hard to see the boshi. It is definitely a suguha boshi and there appears to be a ko maru with a longish kaeri on the omote. The ura is very hard to see.

Jitetsu - Because of the polish on this sword it is hard to see the hada. It appears to me to be itame with a great deal of masame, especially near the hamon. There is no utsuri visible.

Nakago - The sword is o-suriage with a kiri jiri. Yasuri mei are o-sujikai. The patina on the nakago doesn't look very old.


This sword was purchased at a gun show. (The other weren't). It had a junk cast tsuba, and junk menuki. It had a high quality fuchi that didn't fit, a horn kashira, and an extremely bad hilt wrap.

It had one original seppa and the original tsuka with very high quality same. I find this typical of gun show swords. Did some dealer take the good original fittings off, or did the Japancese owner do it before he turned it in to the American military government? I remounted the sword as it is today, and rewrapped the hilt.

Sword #4

This sword received a 70 point paper at the 1989 shinsa and was attributed to the Bingo Kai Mihara group and was dated at 1530.

It is either a mumei suriage, or o -suriage katana mounted as a gunto. There is an unknow mon on the hilt.

Shape - Modest koshi sori, extremely straight in the monouchi. Sword is very thin from repeated polishing. Wide shinogi ji, high shinogi and extremely high mune, all Yamato traits.

Hamon - Suguha with a tight nioi guchi and a lot of yo. It has nie kozure (the reverse of ashi). There are variations in the width of the nioi guchi.

Boshi - Suguha with a komaru, may have a long kaeri on the ura side, may be tiger tail style. Almost looks like a jizo boshi. Boshi is very well done, which is typical trait of a Koto sword. Note: it doesn't have swelling on back of kissaki.

Jitetsu - Fairly tight itame with a tendency to run or have masame. Beginnings of a bo utsuri near the hamachi. There may be faint shirake utsuri on the omote side.

Nakago - Sword may be suriage mumei rather than o-suriage. There appears to be an original part of the nakago which looks older. This section looks very old.

Percentage of curvature - I am particularly interested in this attribute. Dean Hartley in "The Shape of the Sword" says that the highest known percent of curvature is 4.53%, with the greatest curvature found in Heian and Kamakura periods.

Suguha Swords - Beginning collectors tend to discount swords with suguha hamon, I know I did. The more convoluted the hamon, the better it is, to a beginner. You must realize that the fine crystalline martinsite detail in the hamon, and how it fit's the sword, are what make it interesting. You can have a lot of detail, as in sword #3, or very quiet as in sword #1. Its very quietness and stillness are part of the charm of sword #1. The more mature I become as a collector and student, the more quiet suguha swords appeal to me.


The Nihonto Newsletter by Albert Yamanaka

The Inaka Smiths, 1975 JSS/US Bulletin by Albert Yamanaka

Japanese Swordsmith Groups by W. M. Hawley

A primer of Japanese Sword Blades by B. W. Robinson

Token to Rekishi, various issues, journal of the NTHK

Token Bijutsu, various issues, journal of the NTHK

Nihonto Kantei Hitsukei by Fukunaga

Nipponto, Art Swords of Japan (Compton Catalog) by Compton, Homma, Sato and Ogawa

Nihonto Zuikan - Kotohen by Kataoka

The Book of the Sword edited by Tom Buttweiler

Japanese Sword smiths Revised by W. M. Hawley

* Note : As a result of publishing this article on the internet, some new information has been provided by a fellow collector. The sub group of Shimbo (mentioned above in the Chu Mihara section) may be read as Tokifusa. Soten Uchida, who investigated Yamato and Yamato-related groups very well in the pre-WWII period, wrote about Tokifusa (Shimbo) in his book "Dai-Nippon Token Shin-kou" (1933) The information in the later 1935 edition is as follows: "Tokifusa is probably the name of an area, but presently we don't find an area of this name. I think this name is read Tokifusa."