NBTHK SWORD JOURNAL
ISSUE NUMBER 674
Appreciation of Important Swords
Classification: Tokubetsu Juyo Token
Mei: Bishu Osafune ju Motoshige
Kano 3 nen 8 gatsu hi (1352 A.D.)
Length: 2 shaku 3 sun 8 bu 9 rin (72.4 cm)
Sori: 6 bu 6 rin (2 cm)
Motohaba: 8 bu 9 rin (2.7 cm)
Sakihaba: slightly less than 5 bu 8 rin (1. 75 cm)
Motokasane: slightly less than1 bu 7 rin (0.51 cm)
Sakikasane : slightly over 1 bu 4 rin (0.43 cm)
Kissaki length: 8 bu 9 rin (2. 7 cm)
Nakago length: 7 sun 6 rin (21. 4 cm)
Nakago sori: 7 rin (0.2 cm)
This is a shinogi zukuri tachi with a mitsumune, a standard mihaba, and the widths at the moto and saki are different. There is a standard kasane, a large koshisori, and a chu-kissaki. The jihada is ko-itame mixed with mokume and nagarehada, and the entire jihada is visible. There are dense ji-nie, fine chikei, jifu, and midare utsuri. The hamon is based on a wide suguha mixed with gunome, ko-gunome, and square shaped gunome, and on the koshimoto there are prominent kaku-gunome (sqaure shaped gunomme); the entire hamon shows saka-ashi. There are frequent ko-ashi and yo, and a tight nioiguchi with freqent ko-nie and fine sunagashi. The boshi on the omote is straight, and on the ura it is a shallow notarekome. Both sides have a wide yakiba with a komaru and return. The horimono on the omote and ura are futasuji-hi with marudome. The nakago is ubu with a slight alteration at the machi. The nakago tip is kurijiri, and the yasurime are a shallow katte-sagari. There are three mekugi-ana. On the omote, on the upper half on the shinogiji, there is a small sized long fine signature, and the ura has a date.
The Bizen Osafune school smith Motoshige belonged to a different group than Kanemitsu and Chogi. According to old sword books, he belong to the Hatakeda Moriie group, and the Nidai Moriiefs son is Morishige and his grandson is Motoshige. His active period was at the end of the Kamakura period around Showa 5 (1316), Bunpo, Gen-o, Genko, Karyaku, and into the to Nanbokucho period eras of Kenmu, Kan-o,Bun-na, Enbun, and Joji (1365). This is a 50 year span and a long time for a smith to work. His jihada are mixed with nagare-masame hada and jifu, the hamon are prominent and contain square shaped gunome and saka-ashi. There are hataraki such as saka-ashi and yo, and rarely, his boshi remind us of the Aoe school, and these are his and the schoolfs characteristic points. Among his works some show strong nie, and from the period and his nie, people thought that he was one of Soshu Sadamunefs Santetsu (three best students). However, today there is no good evidence to support this. His hamon styles are both wide and narrow, but more often we see the narrow style. His tachi jihada are itame mixed with mokume and nagarehada, and the entire jihada is visible; there are dense ji-nie, fine chikei, jifu, and midare utsuri. The hamon is based on suguha, and contain gunome, ko-gunome, ko-choji, and square shaped gunome, and the entire hamon has saka-ashi, and these features exhibit Motoshigefs characteristic style very well.In particular, there is a tight nioiguchi with frequent ko-nie, frequent ko-ashi, and yo. Beside a wide hamon, there is a beautiful balance of the mihaba and hamon, an excellent hamon, and this is a refined and healthy work with an ubu shape which is rare for this period. There is a similar tachi signed Bizen Osafune ju Motoshige, and dated Kan-o 4 nen 12 gatsu hi (with a length of 2 shaku 8 sun 5 bu 5 rin), which is owned by the Tokyo National Museum and which was formerly owned by the Danzan shrine.
This tachi was owned by Kanin no Miyake (a royal family), and has a mid-Edo period koshirae with kin-nashiji work, kiku and kiri mon chirashi makie, and a itomaki no tachi koshirae style. Also, in the Kosan oshigata, there is a sword listed which is very similar to this one and which is supposed to be this tachi.
Explanation and oshigata by Hiyama Masanori
Appreciation of fine tsuba and kodogu
Kuro-ishimeji nuri saya Satsuma uchigatana koshirae:
A Satsuma uchigatana koshirae with a black lacquer decorated saya.
The entire suite of kodogu was made by Ishiguro Masami
Mei: Jugakusai Ishiguro Masami with kao
Since historical times, the Satsuma clan had a reputation for producing very serious or dedicated warriors. This is illustrated very well in the mid-Edo period by the clanfs original Jigenryu kenpo school. This schoolfs style focused their sword fighting techniques on the first stroke: the idea was to hit with a very intense stroke which was likened to tearing the air, and just one stroke was intended to kill their opponent. This was a very cruel fighting style. Most of Satumafs koshirae are made to support this fighting syle. The tsuka are thick and long, there is not much tapering in the center of the hilt (ryugo); the fuchi is thick, the same as the kashira; most of the koshirae do not use same skin; the tsukamaki style is usually g hira-maki g (use of two strings) or gkatate-makih (use of only one string) and there are usually no menuki. The schoolfs philosophy is that ga sword is a weapon for attacking the enemy, and not for protecting yourself. g From this, the function of the tsuba is only to protect the swordsmanfs hand from slipping, so many of their tsuba are small. In addition, the schoolfs teaching was not to use a sword rashly, and usually the saya and tsuka were tied together with a string. Whena katana was drawn, the katana with saya was withdrawn from the obi and then used to attack an enemy. Adapting to this fightling style meant that the Satsuma koshirae didnft have orikaeshi shaped tsuno (hooks), but just a smooth bump-like projection to make it easier to pull out the saya from the obi. This koshirae shows these kind of Satsuma koshirae characteristics. However, all the kanagu are work of the Edo master Ishiguro Masayoshi. The Ishiguro Masayoshi and the Satsuma clan were supposed to have a close relationship. Some opinions are that he was the clanfs okakae smith (who worked for the clanfs daimyo) and this koshirae supports this opinion. This is well carved work with bright iroe (colors), and carefully done nuri (paint) work. You can imagine that this likely belonged to a very high class samurai, or to someone in the daimyofs family.
Note that the tsuba is shown in exact size in the photo.
Explanation by Iida Toshihisa.
Shijo Kantei To No. 674
The deadline to submit answers for the No. 674 issue Shijo Kantei To is April 5, 2013. Each person may submit one vote. Submissions should contain your name and address and be sent to the NBTHK Shijo Kantei. You can use the Shijo Kantei card which is attached in this magagzine. Votes postmarked on or before April 5, 2013 will be accepted. If there are swordsmiths with the same name in different schools, please write the school or prefecture, and if the swordsmith was active for more than one generation, please indicate a specific generation.
Length: 2 shaku 1 sun 8 bu (66. 05 cm)
Sori: 7. 5 bu (2.27 cm)
Motohaba: 9 bu 6 rin (2.9 cm)
Sakihaba: 6 bu 1 rin (1.85 cm)
Motokasane: 2 bu 6 rin (0.8 cm)
Sakikasane: 1 bu 3 rin (0.4 cm)
Kissaki length: 9 bu 9 rin (3.0 cm)
Nakago length: 5 sun 4 bu (16. 5 cm)
Nakago sori: 3 rin (0.1 cm)
This is a shinogi zukuri tachi with an ihorimune, a standard mihaba, and the widths at the moto and saki are different. The kasane is a littlelarge (the blade is a little thick), there is a high koshizori, funbari, the tip has sori, and there is a chu-kissaki. The jihada is a itame mixed with mokume and nagarehada, and the entire jihada is visible. There are ji-nie, chikei, pale midare utsuri on mune side, and straight utsuri on the ura side. The hamon and boshi are as seen in the picture. Some places have tobiyaki and ko-ashi. The entire hamon is narrow, and there is a nioiguchi and ko-nie. The horimono on the omote and ura are bo-hi carved through the nakago. The nakago is ubu, and the nakago tip is kurijiri. The yasurime are katte-sagari, and there are two mekugi-ana. On the omote side, the nakago has a long kanji signature between the mekugi-ana located along the center, and the ura side has a date. This smithfs work often shows an characteristic colored jifu and jihada.
Teirei Kanshou Kai For February
The swords discussed below were shown in the February 2013, meeting at the NBTHK headquarters building. This discussion presents answers concerning the makers of these blades.
Date: February 9, 2013 (second Saturday of February)
Place: Token Hakubutsukan auditorium
Lecturer: Kubo Yasuko
During these meetings, five swords are displayed for examination. The blades can be examined, but the nakago are covered and cannot be seen (they are left in the shira-saya tsuka). After examining the 5 swords, the meeting attendees must decide who they think made the 5 swords which were available for examination, and submit a paper ballot with these names. The 5 swords seen in the February meeting are described below, and the correct names of the makers are presented, along with an explanation of important details which should help a person to pick the correct swordsmithfs name.
Kantei To No. 1: tachi
Length: 2 shaku 3 sun 6 bu
Sori: 9 bu
Style: shinogi zukuri
Jihada: itame mixed with mokume hada, some parts of the hada are barely visible; there are dense ji-nie, fine chikei, and soft appearing utsuri.
Hamon: Based on suguha with notare, mixed with ko-choji, ko-gunome, and ko-midare; there are frequent ashi, yo, ko-nie, kinsuji, sunagashi, and uchinoke type yubashiri.
Boshi: shallow notare and yakizume.
Horimono: both the omote and ura have bo-hi with marudome.
This Shigetsune tachi is supposed to have been made around the Kencho period (1249-1255) according to the Meikan, and this has a Honnami Mitsutsutsune origami dated Genroku 8 nen. Shigetsune does not have many signed blades. There is a similar work and signature which is similar to this tachi, and which is classified as Juyo-Bijutsuhin and owned by the Keikado Bunko museum.This blade has a narrow mihaba, high koshizori and a small kissaki, which is a classic shape. The jihada has pale utsuri. The suguha hamon has a shallow notare mixed with ko-choji, ko-gunome, and ko-midare, and there are frequent ashi and yo, and these features show the Ko-Bizen character very well. Among Ko-Bizen swords, this one has a unique character. This sword should be compared with other Ko-Bizen, Ko-Aoe and Ko-Kyoto work from the end of the Heian period to the early Kamakura period. Many of their habakimoto are about 3 sun wide and that area has a narrow yakiba. However, Shigetsunefs signed tachi both have a koshiba which is wide and prominent. This tachi has a high yakiba right the above habaki, and considering the machi shape it has today, it is possible that there was a koshiba there. In the first vote, about half of the people looked at this as Ko-Bizen work by smiths such as Masatsune and Tomonari. The other votes were for mid- to late-Kamakura smiths such as Nagamitsu, and some people voted for other prefecturefs smiths such as Rai school smiths. At first, you look at the location of the sori, the kissaki shape, and the characteristics of each shape and the condition. Also, please notice the good condition of the nie.
Kantei To No. 2: tachi
Mei: Takatsuna (Bishu)
Length: 2 shaku 3 sun 1 bu
Sori: 7.5 bu
Design: shinogi zukuri
Jihada: itame mixed with ko-mokume hada, and the fine hada is visible. There are dense ji-nie, fine chikei, jifu, and jifu utsuri.
Hamon: based on suguha, and mixed with ko-midare, ko-choji, and ko-gunome. There are frequent ashi and yo, dense nie, strong nie in places, hotsure, yubashiri, nijuba, and frequent kinsuji and sunagashi.
Boshi: straight with a komaru.
Takatsuna is listed as a Ko-Bizen smith in the Meikan along with other three other smiths who were active around the Genkyu, Kangen,and Kocho eras (these dates span the period from 1204 to 1263). Also, these smiths are listed with other schools such as Nio and Kongobyoei. The characteristic jihada and hamon, thick ha-mune (mune edge of the nakago) on the nakago, the osujichigai yasurime, and the large sized two kanji signature with gyaku-tagane strokes on the ura side of the nakago are the expected Ko-Aoe characterisitcs. As a compairson, for the No.1 Kantei To above, we displayed a Ko-Bizen tachi. At the end of the Heian to the beginning of the Kamakura period, Ko-Bizen and Ko-Aoe blades had similar shapes and hamon and are similar, and sometimes it is easy to confuse them with ech other. In judging them, the important points are the jihada, type of utsuri, and the nioiguchi. This sword has itame hada mixed with ko-mokume; the hada is visible; and there are jifu utsuri. The hamon is based on suguha mixed with ko-midare, ko-choji, and ko-gunome, and there are dense nie. As you know, the Ko-Aoe jihada is mixed with mokume hada, and the fine hada is visible, and there are jifu. In particular, the shape of the jifu areas are uneven, and there are more strong nie compared to Ko-Bizen work, and the nioiguchi are more worn down. In voting, many people recognized the difference between Ko-Bizen and Ko-Aoe work, and voted for Ko-Aoe smiths such as Sadatsugu, Tametsugu, and Yasutsugu. Also, people voted for Ko-Bizen in the first vote, but voted for the correct answer in the second vote which was a good outcome. Of course, it is difficult to judge individual smithfs names, and if you look at this as a Ko-Aoe school smithfs work, it would be good enough. Some people voted for same prefecturefs Imo-o school smiths, much as Noritaka and Masatsune. This school was in Bishu and active at the same time as Ko-Aoe, and has a similar style, so this was treated as a correct answer, however, many of their nioiguchi are brighter and have more nie.
Kantei To No 3: tanto
Length: 7 sun 4 bu
Style: hira zukuri
Jihada: tight ko-itame mixed with mokume hada; there are dense thick ji-nie, frequent fine chikei, and nie utsuri.
Hamon: the lower half is a suguha style with a shallow notare; the upper half is ko-notare mixed with gunome, and there are ashi, a wide nioiguchi, frequent ko-nie, and fine sunagashi.
Boshi: the omote side is midare komi, tsukiage, and the tip is sharp; the ura side is suguha with komaru, and has kinsuji; both sides have hakikake and a long return.
Samonji used to be called Dai Sa or Great Sa, and supposedly he was a grandson of Seiren and Jitsuafs son. As you know, Samonji changed the Kyushu classic schoolfs style to a new style. Among his signed blades, one is dated in Ryakuo 2 (1339). Looking at the Ryakuo 2 work, there is a darker color jihada with whitish utsuri and a suguha hamon with a worn down nioiguchi, so he was still working in a classic Kyushu style at that time. His great student Yukihirofs Kokuho blade was dated during the Kan-o era and has a notare hamon mixed with gunome, and both the jihada and hamon are bright and clear which is a Samonji style. Thus the Samonji style is supposed to have been established during these ten years. This tanto is smaller than a Nambokucho period work, and there are smiths who used the same type of shape such as Shidzu Saburo, and Chogi. Many of them have a standard mihaba, but a poor fukura is part of Samonjifs characteristic style. Both the jihada and hamon on this tanto have frequent ko-nie and are bright. The hamon is notare mixed with gunome, the boshi on the omote side is tsukiage with a long return, and this shows his original style which he established. From this, one can arrive at many correct answers. The boshifs return is a little tight, and from the condition of the habakimoto, you can guess there was a koshiba there. People seem to have a sufficient recognition of these small details. Some peole voted for Yasuyoshi and Rai Kunimitsu. Yasuyoshi has a few smaller sized tanto, but most of his tanto are large with a wide mihaba, his utsuri are whitish, his hamon are a nioiguchi type, and his boshi have a slanted shape. Rai Kunimitsufs jihada and hamon are certainly similar to this, but his shapes are typical of the style from the end of the Kamakura period.
Kantei To No 4: tanto
Length: 7 sun 8.5 bu
Design: hira zukuri
Jihada: itame mixed with o-itame and mokume hada; there are frequent dense ji-nie, frequent thick black chikei, and a dark color jihada.
Hamon: high yakiba; the moto has a short yakidashi; based on a shallow notare mixed with gunome; the habuchi has hotsure; there are nie ashi, a dense nioiguchi, frequent large nie, and a worn down nioiguchi; between the jihada and hamon there are soft, frequent long niesuji, kinsuji and sunagashi over the entire mune; there are swirl shaped yubashiri, and the tanto is a hitatsura style.
Boshi: shallow notarekomi; the omote is yakizume, the ura has a short return, and both sides have frequent sunagshi and kaen at the tip.
This tanto has a standard mihaba and length with a mitsumune and uchizori. The hamon has a high yakiba; there is a smooth midare hamon, and there is a dense nioiguchi; the nie between the ji and hamon appear soft, and there are frequent niesuji, kinsuji and sunagashi. The jihada has yubasihri with a continuous spiral-like shape, and the overall appearance is like hitatsura. This is a very characteristic Norishige work, and many people voted for his name in the first vote. Undoubtedly, duirng the Kamakura period, among the Soshu Den master smiths, Norishige was a very unique smith, and this tanto shows his attractive characteristics very well. The shape is uchizori, there is a poor fukura, a sharp angled mitsumune, and this is characteristic of his shape. The jihada is dark, and shows his unique mokume hada which mixes hard and soft steel together very well. There are strong chikei which are called gMatsukawa hada.h This tanto has a yakiba which runs very close to the mune. Since the hada is not too visible, and it not easy to see the details of the jihada, but if you you look carefully, there are conspicuous frequent lines of chikei. Anyway, as I metioned, the results from the voting was great, but a few people voted for Hankei. His work seems to modeled after Norishigefs, and this tanto has a large kasane, so from this viewpoint it is understandable. But his shapes have a wide mihaba, and either a long length or have a short chubby shape with a shallow sori.
Kantei To No. 5: katana
Kinzogan mei: Chogi
Length: 2 shaku 3 sun 2 bu
Sori: 5 bu
Design: shinogi zukuri
Jihada: tight itame; there are frequent dense ji-nie, fine chikei, and pale midare utsuri.
Hamon: there is a high yakiba; the hamon is choji mixed with gunome and square shaped gunome; this has a yamazata (mountain shaped) midare hamon with a beautiful midare; there are ashi, yo, frequent shimaba, frequent ko-nie, and in places, there are ara-nie, uchinose, yubashiri, frequent kinsuji and sunagashi, and a slightly worn down nioiguchi.
Boshi: midarekomi with yubashiri, and tobiyaki mixed with hakikake; on the omote side the tip is sharp; on the ura side the tip is a maru (round) type; both sides have a long return.
Horimono: both the omote and ura sides have futasuji-hi carved through the nakago.
This katana has a very wide mihaba, and the widths at the moto and saki are not much different; there is an o-kissaki and very dynamic shape. Even without the hiraniku, this feels heavy in hand, and this may be because of the shape or the design of the katana. In the first vote, many people voted for Shinshinto smiths such as Kiyomaro and Naotane. But the jihada and hamon are so different that many people changed the era and voted again with an individualfs name. Chogifs utsuri are often pale, and there are strong nie in the jihada and hamon; the hamon patterns are large, and have with his unique yamagata midare hamon. There are frequent ashi and yo, yubashiri, tobiyaki. There is a very active and beautiful hamon. The boshi is midarekomi with a sharp tip and return. Also, Chogi often has hi carved through the nakago. So, if you catch the era correctly, this is a typical Chogi work. This blade is wide with an o-kissaki, and for the mihaba, the shinogi-ji is narrow, and this kind of shape is seen in Bizen work. Two of best master smiths callwho worked in the gSoden Bizenh style are Kanemitsu and Chogi. Chogifs work adopted more Shoshu Den characteristics than Kanemitsufs, and in historical times, people used to say that his work and style is the most distant from the Bizen style. Among the Bizen smiths, beside Chogi, some people voted for the same erafs smith Kanemitsu and Sue-Bizen smiths such as Kiyomitsu. Kanemitsu does not have such spectacular work, and most of his hamon are primarily notare or have square shaped gunome. Sue-Bizen hamon have open-bottom mountain shaped midare hamon and sometimes nijuba is present, and similar hamon styles are seen in places but they donft have blades with such a wide mihaba, and the lengths are shorter, they are thick, the shinogi-ji angles sharply from the ji, and they have a high and strong sakizori shape.
Shijo Kantei No 672 ( 2013 New Yearfs issue)
The answer for the Shijo Kantei To No. 672 in the New Yearfs issue is a katana by Etchu-no-kami Takahira (the same smith as Kashu Kanewaka), dated Genna 8 nen.
The Shodai Kanewaka is known as one of the best master smiths in the Keicho Shinto period. He work is highly valued in his home town, and since historical times people have studied sword books such as the gKashu Shinto-shuh and the gKashu Shinto-Taikanh. On the other hand, people used to say that g Kanewaka is a hako-ba midare hamon smithh and there seems not to have been much study or attention to his work. Thhis may be because we doft have many chances to look at his work. At the Juyo Token and Hozon-token shinsas, very few of his works are seen compared to the Shodai Tadayoshi, Horikawa Kunihiro, and the Shodai Yasutsugu. I am guessing that number of his signed blades are very small among the Keicho shinto smiths. Concerning Kanewakafs active period, there are not many ideas about when he started working, but today his signed blades are seen dated from mid-Keicho to the early Kanei period. The Keicho shinto smith Horikawa Kunihiro who was active from Keicho 1 to the end of Keicho, but Kanewakafs active period was later his, and seems to be at the same time as the Shodai Tadayoshi who has dates from Keicho 5 to 10, and Nanki Kunishige who was active from the end of Keicho to the second half of the Kanei period, and these two are later Keicho shinto smiths. Around the Keicho period, Kanewakafs early works have a prominently wide mihaba, and the widths at the moto and saki are almost the same. There is a very shallow sori with an o-kissaki which is a typical Keicho shinto shape. This katana definitely reminds us of a Nanbokucho period Enbun-Joji style o-suriage tachi shape. In this case, the jihada is a visible itame hada, or itame mixed with nagarehada, and there is a visible hada. There are frequent ji-nie, and chikei. Kanewakafs hamon are a very narrow yakiba for the wide mihaba, and are a shallow notare mixed with ko-gunome and ko-togariba, a notare type hamon mixed with gunome, or a notare type hamon mixed with continuous large size gunome and togariba. The hamon are often have hotsure, and there are nie, kinsuji and sunagashi, which reminds us of a classic Mino style, such as Shidzu.
In the period from Genna to Kanei, when he started to use the Takahira signature, his shapes changed to have an almost standard mihaba, and the widths at the moto and saki were slightly different. There was a chu-kissaki and a slightly large sori when comparedto his earlier work. His jihada are primarily a finer tight itame hada when compared with earlier work, and was sometimes mixed with nagarehada. Around this time, there are often notare hamon with gunome, and a wider nioiguchi with nie. This is a similar style seen all over the country around the Kanei period, and a typical Shinto style, which was then a contemporary modern style with a prominent nioiguchi.
Kanewakafs characteristic hako- midare hamon is seen prominently among his hamon around this time. The Shodai Kanewakafs hako-midare hamon do not always have a typical hako shape (square gunome), and often there is a wide nioiguchi mixed with nie-kuzure. But after the Nidai Kanewaka, the other Kashu Shinto smiths made more clearly shaped hakomidare hamon. Kanewakafs early boshi are midarekomi with a sharp tip, or a midarekomi with a sharp tipped komaru and return. Later boshi are straight with a komaru, or a shallow notarekomi with a komaru.
During the Keicho period, many later smiths changed their styles with time. For example, in his early work, Kanewakafs favorite styles are based on classic Nambukucho work. In the Genna and Kanei periods, he change his style to follow the Shinto period modern style, which were seen every. Later he established his own schoolfs style, and passed it on to the next generation. This kind of movement is also seen with the Shodai Tadayoshi and Nanki Shigekuni. Kanewakafs horimono are bohi, futasujihi (often seen in katana), bonji, yo style kurikara, characters in ukibori (carving), three Budhas, and sho-chiku-bai ( pine, bamboo, and plum). His nakago tips are kurijiri, his yasurime are sujicihgai, osujichigai, and katte-sagari.
When he used the Takahira name, he signed gEtchu no kami Fujiwara Takahirah and gTsujimura Echu-no-kami Takahirah. On shinogi zukuri katana, he often signed on the omote, close to the mune edge. When he use Tsujimura name, he often signed two lines. Sometimes signatures are seen with a date, and the Takahira name is seen with a kao sometimes. In voting, most of people voted for Etchu-no-kami Takahira (the Shodai Kanewaka). A few people voted for smiths working after the Shodai Kanewaka, such as Matasuke and Shirouemon, or other Kashu smiths working around Kanewaka such as Dewa-no-kami Takahira. These smiths have hako-midare hamon examples, and their works are similar, and sometimes Matasuke and Dewa-no-kami Takahira have two line signatures with a kao. However, Kashu Shinto smiths have not been studied very extensively, so for this reason, at this time, we treated these smiths names as correct answers. As I mentioned before, the Shodai Kanewaka does not have many clearly shaped hakomidare hamon, and for later smiths we typically see more hakomidare hamon. Beside these smiths names, there were a few Muramasa votes. The jihada is itame mixed with nagare hada, and the hamon is a square shaped midare hamon, and the Shodai Muramasa has some long signatures, so from these points, the answer is understandable. But if were Muramasafs work, the katana shape would be a late Muromachi shape with a strong saki-zori, the jihada is often darker, the utsuri is not exactly white but whitish, and the hamon has prominent up and down variations and square shaped gunome. Also, Muramasa does not have signed blades with a kao, so please note this.
Explanation by Hinohara Dai