Hosho Sadaoki TantoHosho Sadaoki

periodKamakura/Nanbokucho border (ca. 1338)
designationNBTHK Juyo Token Tanto
nakagoubu, 2 mekugiana
nagasa23.4 cm
motohaba1.9 cm
nakago nagasa7.7 cm
nakago sori0.35 cm
price$28,500 -new-

[This blade by Sadaoki] has josun or standard ha-watari, normal mi-haba, uchizori and standard tanto-sugata of the late Kamakura Period. In addition, it has thick kasane in disproportion to mi-haba and it is one of features of the Hosho school. The jihada is pure masame-hada. The grains of the masame go up toward the mune line in the fukura area also they go down toward the ha-machi in the bottom area. [The Hosho smiths] temper hamon with many vertical hataraki like hotsure, niju-ba, kuichigai-ba, hakikake, kinsuji and sunagashi as seen in a tanto by [Sadayoshi], Kuwayama Hosho designated as Kokuho. Meanwhile they temper sugu-ha with calm hataraki like the hamon of this tanto too. Though, you can see a lot of very fine hataraki like hotsure, niju-ba, kuichigai-ba, etc. in the hamon which consists of beautiful and shiny nie which is superior to that of Sue-Tegai and Sue-Hosho smiths. NBTHK Token Bijutsu on an example blade by Hosho Sadaoki blade

The Yamato tradition is generally broken down into five schools, Senjuin, Taima, Shikkake, Hosho and Tegai.

The Hosho school was located in Takaichi-gori (Takaichi-gun) of Yamato province. This school is unique in these in that their name is not coming from an association with a temple, but is a family name recorded on one of the swords by Hosho Sadamune 保昌貞宗 in the Kamakura period. Old books actually refer to Hosho Kunimitsu as the founder, but his blades are not found today.

The Nihonto Koza refers to the confusion around the founding of this ha, saying that Hosho Kunimitsu is the same person as Hosho Sadamitsu, and that in one account Kunimitsu is the father of Sadayoshi who is the father of Sadamune. In another, Sadayoshi and Sadamune are brothers, both sons of Kunimitsu. There are dates on existing works by these smiths, Sadayoshi having a date of 1317 and Sadamune having a date of 1318.

Detail of Juyo Hosho Sadaoki Tanto

Making matters a bit worse, the Nihonto Koza refers to a sword with a signature of Sadatsugu 貞繼 that:

... shows the highest degree of technical skill, has one level more of an antique tone than the works of both Sadayoshi and Sadamune, and this impression is especially strong in the mei style. However, the fact that this name is omitted from the usual meijin and meikan books is strange.

Lovers of Yamato swords learn to accept these kinds of open questions in the history of this tradition, as so few signed pieces exist and mysteries continue to abound.

One thing that is clear is that the traits of Yamato swords are something that everyone encounters very quickly in sword study. Not very much is written about Yamato, but we always hear the mantra of high shinogi, wide shinogi-ji, yakizume boshi, few signatures, hotsure in the nie hamon, and masame hada.

Among the school’s work, some blades have dense nie from the edge up to the inside of the habuchi; the hamon is bright and clear; there are frequent kinsuji and sunagashi; and the boshi has frequent hakikake. There is abundant hataraki. Other work from this school shows narrow bands of nie, less kinsuji, sunagashi and hakikake, and are somewhat gentle looking.

Because of their unique entirely masame jihada, the Hosho school name is famous, but there are very few swords extant today. These include tachi and tanto with signatures, katana without signature. These blades have classifications of Kokuho, Juyo Bunkazai, Juyo Bijutsuhin, Tokubetsu Juyo, and Juyo Token. The number of signed blades is 23, and the number of clearly identified works without a signature is around 45. Thus we do not have many chances to see work from this school today. [Note: this is from an older document, another 30 or so blades have been established.]

NBTHK Token Bijutsu

Detail of Juyo Hosho Sadaoki Tanto

As one studies deeper into Yamato, it becomes evident that masame is not very frequent at all as a form of construction in these schools, but that it shows up as a flavoring in the itame and mokume that is the actual basis of construction of Yamato swords. Han Bing Siong made a point of counting how many Juyo Token he could find from the various Yamato schools that were produced in pure masame.

  1. Shikkake: 5 masame out of 82
  2. Senjuin: 3 masame of of 80
  3. Taima: 2 masame out of 159
  4. Tegai: 1 masame out of 48

This gives a very clear conclusion that the diagrams encountered in the references that pound home the association of pure masame with Yamato are not so accurate. What is true though is that the Hosho school specialized in masame, and it is the presence of masame in this school that is the source of these diagrams above.

The Hosho school demonstrates a very unique workmanship in Yamato Province and is differentiated from other four major schools of Yamato Province. That is to say, the jihada is well-forged and pure masame-hada. The grain of the masame in the boshi area goes through to the mune line and the one in the bottom to the fine edge. Also open hada called kata-ware are seen in places and hamon is tempered on the basis of sugu-ha then hotsure, kuichigai, uchinoke and niju-ba are seen, and boshi becomes yaki-tsume with hakikake (the hamon tend to be wide in the boshi area). In addition, their blade has thick kasane and nakago has kiri tip and higaki-yasuri. NBTHK Token Bijutsu

Fujiwara Sadaoki Tokuju Tachi
Fujiwara Sadaoki Tokuju Tachi

Construction in masame is very difficult, as the welds form very long seams that take great skill to make perfect. As such, most blades in masame show ware along the welding lines. For the Hosho school these masa ware are not considered flaws, but are considered a kantei point and a hallmark of the school.

The Hosho school marked their nakago with the higaki style of yasurime. Their tachi have shallow kurijiri tips, but their tanto have the kiri or the straight-across end cut. The Hosho school is characterized with a most distinct type of workmanship producing neat and uniform masame grain.

The smiths from this school all included the letter SADA to name themselves Sadayoshi, Sadamune, Sadaoki, Sadakiyo, and so on. It is not to exclude the other four Yamato schools as possible producers of perfect masame grain in the ji, but such perfectly masame structure blades are exceedingly rare among their examples, although almost all of them contain some straight grain in the kitae. NBTHK English Token Bijutsu

Detail of Juyo Hosho Sadaoki Tanto

Anyone can draw a wavy line and it is impossible to tell within those patterns of waves what is intentional and what is jitter. In the same way any attempt to draw a perfectly straight line betrays the artist because any deviation from perfection stands out immediately. In this way excellent suguba is hard to form and as well, perfect masame has the same issue. Given that these are indirect or blind processes, achieving excellence in masame and suguba is something that reveals the skill of the artist.

Masa-ware are side effects of this process as the folding in itame and mokume naturally limits flaws. Straight grain is harder to weld and more subject to displaying these flaws and we do see this on Hosho blades even of the highest caliber. All of this difficulty may be why so few other smiths even attempted masame and is potentially a pride item in Hosho deciding to specialize in them. This blade does have one in the monouchi area, but due to its construction we forgive these in Hosho works. This is attested to by Tanobe Michihiro sensei as follows:

Even though Hosho's works often show tate-ware (vertical crease) in the masame, it has traditionally been positively recognized as a unique trait of their forging, and has never been counted as a fault Tanobe Michihiro, retired head researcher, NBTHK

The top works of the Hosho school rapidly fade away with the Nambokucho period, though it is thought that some works of the Muromachi period are by descendants of this school though the Muromachi period in Yamato province was dominated by the Sue-Tegai smiths.

It is very difficult to single out a smith from them as their workmanships have close similarity but it may possible to do it from sugata. Sadayoshi normally makes tanto with around 27 cm. in ha-watari, a little wide mi-haba and extended ha-watari. Sadakiyo makes tanto with extend ha-watari between 27 and short ha-watari between 30 cm. also 21 and 24 cm. NBTHK Token Bijutsu

There are only a handful of known smiths of this school, Sadayoshi, Sadamune, Sadaoki, Sadamitsu, Sadazane, Sadakiyo and Sadasue. Fujishiro gives the two possible founders a uniform rating of Jo-jo saku, and the students all Jo-saku for superior workmanship. My feeling is that with little material to judge, the grades here have a degree of estimation to them. Dr. Tokuno assigns Hosho Sadakiyo a high score of 900 man yen in his rating in the Toko Taikan, making him very valuable, on a par with Ryumon Nobuyoshi (Jo-jo saku) and other Jo-jo saku smiths.

Among signed pieces known today there are the following signatures:

  1. Fujiwara Sadayoshi: 1
  2. Takaichi ju ~ Kingoto Sadayoshi: 2
  3. Takaichi ju ~ Kingoto Sadayoshi Saku: 1
  4. Washu Takaichi Kingoto Sadayoshi: 1
  5. Yamato Kuni Takaichi (cut off): 1
  6. Yamato Kuni Takaichi-gun Junin Saemon-jo Sadayoshi: 2
  7. Yamato Kuni Takaichi ju ~ Kingoto Sadayoshi: 1
  8. Sada~ (Unknown): 1
  9. Sadatsugu: 1
  10. Sadakiyo: 3
  11. Fujiwara Sadakiyo: 4
  12. Sadaoki: 2
  13. Fujiwara Sadaoki: 2
  14. Yamato Kuni Fujiwara Sadaoki: 1
  15. Yamato Kuni ju Fujiwara Sadamitsu: 2
  16. Hosho Sadamune Saku: 1

One note here is that the Hosho Sadamune is Jubi and is not currently regarded as valid. From the rest it can be seen that the Hosho smiths did not use Hosho in their signatures but preferred the clan name Fujiwara. This list is comprised of Juyo, Tokuju, Jubi, Jubun and Kokuho blades. So overall we can see that signed Hosho pieces are extremely rare.

Overall the NBTHK has authorized 71 Hosho only at Juyo and higher. Two of these are tachi, 37 are Katana, 6 are wakizashi and the remaining 26 are tanto. There are another 5 are Juyo Bijutsuhin, 3 are Juyo Bunkazai and one Kokuho. The Kokuho blade is the Meibutsu Kuwayama Hosho that was owned by the Maeda daimyo. The Hosakawa, Date, Yamanouchi daimyo also owned Hosho on the list above as well as the Tokugawa Shoguns themselves.

Juyo Token Hosho Sadaoki Tanto

Juyo Token Hosho Sadaoki Tanto

This is a particularly gorgeous work with a clear attribution to Hosho Sadaoki. As above those with smaller size generally go to him and the hamon and construction of this blade are perfectly representative of the school and specifically Sadaoki. There are only seven works of his at the Juyo and Tokuju levels from which one may choose. This is not due to a lack of skill as he is one of the famous Hosho smiths, but simply due to rarity (all Hosho works are rare and then those going directly to an individual are even more so). Of the 7 at Juyo and higher, 3 have passed Tokuju which indicate the outstanding skill level of this smith.

The best Hosho style forging, the grain is straight masame but overall forms an S shape, as the smith bent the straight billet out so that the grain parallels the cutting edge at the kissaki and an opposite bend is formed right at the machi so that the grain turns off and goes out the end of the sword right there. This shape of grain then makes a natural home for the hamon, as the hamon can go out the kissaki end in yakitsume following the grain, and then can naturally follow the grain off the sword at the machi. It is one of the brilliant traits of this school and attested to by the following remarks on kantei of a Sadaoki in the Token Bijutsu:

Detail of Juyo Hosho Sadaoki Tanto

Further, the basically suguha hamon of ko-nie structure characterized by fine hotsure, sunagashi, kuichigaiba, and uchinoke-gokoro, and with a widening above the monouchi to form a boshi in yakitsume style accompanying outstanding sunagashi, is specifically indicative of Hosho, the most classical of the major Yamato schools. The Hosho school produced masame-hada consisting of fine and thick ji-nie, where there are many long chikei formed. Their masame has an appearance of flowing toward the edge, of which this is a typical example. NBTHK Token Bijutsu

Detail of Juyo Hosho Sadaoki Tanto

This kind of nakago is often referred to as furisode, and while true sometimes furisode is used to refer to a straight and tapering nakago. Furisode refers to a type of tapering sleeve of a kimono and it may or may not be curved. This kind of shape with deep curve in a tanto nakago though comes from the Kamakura period and it is one of the things that helps date this blade. The reasons for this I believe are for use as a metezashi, that is such a tanto is worn on the back of your hip. This makes it easy to grab in body to body grappling, and a curved nakago forms a pistol grip that is easier to grab and draw from behind than a straight nakago (put your hand toward your back and imagine it and you will immediately understand the benefit as the curve fits the natural position of your hand). The flat jiri at the end is also a trademark of the Hosho smiths. They cut these straight which I think is an artistic flair which is a reflection of the straight and regular lines of the jihada, and hamon found in their work.

Hosho Sadaoki has had a long reported work span of 1319 to 1368 but this is not likely the case from the existing work. There are relatively no dated works of the Hosho school and from the characteristics of his work, including the tachi above with essentially a ko-kissaki and the curved Kamakura period nakago of this tanto, he can be placed at the end of the Kamakura period. The Nihonto Koza indicates he is said to be a son of Hosho Sadamune as well which would help indicate a date for him. Fujishiro places him in the first couple of years of the Nanbokucho period at 1338.

Given the rarity of Hosho examples and the beauty of this one, it is I think a really great example for any collector to have in their collection. Some Hosho attributed blades don't develop all of the masame features and so have weaker attributions. This one shows everything exactly as it should be, right down to the boshi and the beautiful small activities and gorgeous jihada. This tanto was found relatively recently in a rusted condition and restored by an American collector who smartly recognized it for what it was. Furthermore, its features making it directly attributable to an individual Hosho smith make it an unusual and welcome find.

Detail of Juyo Hosho Sadaoki Tanto
Hosho Sadaoki Tanto OshigataHosho Sadaoki Tanto Origami

Juyo Token Tanto

Appointed on the 18th of October, 2016 (Session 62)

Tanto, Mumei, Hosho Sadaoki


*hira-zukuri*, *mitsu-mune*, normal *mihaba*, rather small dimensioned size, relatively thick *kasane*, *uchizori*


overall fine and densely forged *masame* that tends somewhat to *nagare* and that features plenty of *ji-nie* and fine *chikei*


*nie*-laden *suguha-chō* with a relatively wide *nioiguchi* that is mixed with a little bit of *ko-gunome*, *ko-ashi*, and fine *hotsure*, *kinsuji*, and *sunagashi* along the *habuchi*


widely hardened *sugu* that runs back in *ō-maru*-style but out as*yakitsume* and that shows plenty of *hakikake*


*ubu*, very shallow *kurijiri* that almost appears as *kiri*, indiscernible *yasurime*. two *mekugi-ana*, *mumei*


From extant (signed) works we know that the Hoshō School was residing in the Takaichi district (⾼市) of Yamato province. The school flourished from the late Kamakura to the Nanbokuchō period and its most well-known smiths were Sadamune (貞宗) and Sadayoshi (貞吉). Also very skillful were Sadakiyo (貞清) and Sadaoki (貞興) and so we learn that the Hoshō smiths shared the character for *Sada*. The workmanship of the school is the most unique of all of the Five Major Yamato Schools and distinguishes itself through a forging in pure *masame* and a tang finish that features *higaki-yasurime*.

This *tantō* shows a *jigane* in a fine and dense *masame* that features plenty of *ji-nie* and fine *chikei*. The *hamon* is a*nie*-laden *suguha-chō* with a relatively wide *nioiguchi* that is mixed with a little bit of *ko-gunome* and fine *hotsure*, *kinsuji*, and *sunagashi* along the *habuchi*. Thus, the *jiba* truly reflects the characteristic features of the Hoshō School and as the *tantō* is rather small dimensioned, the most suitable attribution within that school is to Sadaoki. The typical *masame* is dense and marvellously forged and the steel is bright. The *hamon* features an abundance of beautifully sparkling *nie* within the *ha* and plenty of *hakikake* appear in the *bōshi* and the *deki* of the blade is excellent.

Hosho Sadaoki Tanto Sayagaki


This sword bears an inscription (sayagaki) by Tanobe Michihiro sensei. He is the retired former head researcher of the Nippon Bijutsu Token Hozon Kyokai (NBTHK). He attributes the blade directly to Sadaoki. This was done before the blade passed Juyo, and I can offer to the future buyer to bring it in and have a backside note added about the Juyo session. Washu is the alternate name of Yamato province.

  1. 和刕保昌貞興
    Washū Hoshō Sadaoki
  2. 生茎無銘也
    Ubu-nakago mumei
    Unaltered nakago and unsigned.
  3. 長七寸七分有之
    Nagasa shichi-sun shichi-bu kore ari.
    Blade length ~ 23.3 cm
  4. 時在丙申松風月探山邉道識「花押」
    Jizai hinoe-saru matsukazezuki Tanzan Hendō shirusu + kaō
    Written by Tanzan Hendō (Tanobe Michihiro) in June of the year of the monkey of this era (2016) + monogram