NBTHK SWORD JOURNAL

ISSUE NUMBER 722

March, 2017

 

 

Meito Kansho

Examination of Important Swords

 

Juyo Bunkazai

Important Cultual Property

 

Type: Tachi

Owner: Tokyo Fuji Museum

Mei: Ichi

 

Length: 2 shaku 3 sun 7 bu 5 rin (72.0 cm)

Sori: slightly over 7 bu 2 rin (2.2 cm)

Motohaba: 1 sun 2 rin (3.1 cm)

Sakihaba: 6 bu 9 rin (2.1 cm)

Motokasane: 2 bu 1 rin (0.65 cm)

Sakikasane: 1 bu 3 rin (0.4 cm)

Kissaki length: 1 sun 6 rin (3.2 cm)

Nakago length: 6 sun (18.2 cm)

Nakago sori: slight

 

Commentary

 

 This is a wide shinogi zukuri tachi with an ihorimune, and there is not much difference in the widths at the moto and saki. It has a large ha-niku (the bladefs cross section is thick in the hamon region), there is a large koshi-sori, and an inokubi style short chu-kissaki. The jihada is itame mixed with mokume and the entire jihada is tight. On the ura side in some areas around the center, the hada is visible. There are frequent ji-nie, chikei, and midare-utsuri, and the jihada is bright. The entire hamon is high and based on choji mixed with o-fusa choji (large clusters of choji), kawazuko-choji, gunome, and togari. There are large vertical variations in the midare hamon. There are frequent ashi and yo, a soft nioiguchi, nioiguchi-type nie, a little bit of yubashiri, kinsuji, and a clear nioiguchi. The boshi is midarekomi, and the tip is yakizume. The nakago is slightly suriage and the nakago tip is a shallow ha-agari kurijiri. The yasurime on the omotefs upper part are migaki-ji, and on the lower part of the nakago, they are rusted and unclear. The yasurime on the ura are katte-sagari. There are three mekugi-ana. On the omote side, above the second mekugi-ana, slightly towards the mune side, there is a mei with the gichih kanji.

 In Japanese sword history, people recognize the importance of Bizen as an important sword producing area. Among the Bizen Den sword schools, a typical feature is a choji midare hamon which was established and popularized by the Ichimonji school in the mid-Kamakura period.

 The school was founded by Norimune in the early Kamakura period. Itfs style is not too different from Ko-Bizen work. The schoolfs nie are a little weak, and the hamon are more artistic, and initially it was called it Ko-Ichimonji. The Ichimonji schools were established in the mid-Kamakura period in Fukuoka and Katayama, in the late Kamakura period at Yoshioka, and in the very late Kamakura period at Shochu (Iwato). In the mid-Kamakura period, master smiths such as Yoshifusa, Sukezane, and Norifusa infused the highest level of art into their work. With their high and wide choji-midare hamon, the schoolfs reputation became established. Their hamon are very distinctive and appreciated, and were very distinctive when compared with Ko-Ichimonji work. The style of the hamon is dazzling and gorgeous, very beautiful and spectacular, and the style was supposed to have been started either by accident, or slowly and deliberately through efforts to produce a practical, beautiful and effective sword. How the school was founded is a very interesting story.

 There are wide beautiful midare hamon seen in several blades with engraved (kebori) kiku (chrysanthemum) mon, and these are called gkiku gosakuh works which are supposed to have been made from the time of the Jokyu-no-ran (battle) which was around 1220. Ko-Bizen Tomonarifs work which was classified as Juyo Bijutsuhin dates from the Katei period (1235-38). After this, there is a Hatakeda Moriie tachi classified as Juyo Bunkazai which is dated Bunei 9 (1272), and which has a hamon composed of choji mixed with gunome, and some kawazuko (tadpole-like) choji. From these works, it is thought that from about this period, the more restrained ko-midare style hamon was changing to a spectacular choji hamon.

 But the use of this hamon style began declining after the Bunei to Koan periods (1274-87), and the hamon widths became narrower, and it is known that the Ichimonji school declined and the Osafune school began to become more popular. Consequently, the strong and powerful choji midare hamon is supposed to have been produced only during these 10 or so years.

 Once the spectacular choji midare hamon lost its popularity, itfs revival and re-appearance waited until the Edo periodfs Ishido school. Re-introducing the work of the many master smiths who produced Bizen-den work in the golden era of the  Japanese sword is a goal of Gendai-to smiths, and this style appeals to many people today.

 This tachi is wide, has a large koshizori, a short Inokubi style chu-kissaki, and has a typical mid-Kamakura period dynamic feeling and a dynamic tachi shape. There is a large hiraniku, and it has been maintained in good condition. The well forged jihada has midare utsuri. The hamon has frequent ashi and yo, is wide, and has many hataraki and large vertical variations. The hamon contains juka choji and kawazuko choji and vertical alterations, and the overall hamon pattern is a large midare which is dynamic and feels full of energy. This is the same kind of feeling we see in the gBo-hime Tsuru Ichimonjih blade classified as Juyo Bunkazai. Certainly this blade shows a clear and present beauty which is the opposite of Soshu Den work which shows a more abstract beauty or dynamism. This tachi is one of the best master pieces we have and easily shows the true character of Fukuoka Ichimonji work.        

 

Explanation by Ishii Akira and photo by Imoto Yuuki.

 

 

 

No.722 Tosogu Kanshou

Juyo Tosogu

 

Koboku (old tree) ni (with) karasu (crow) zu (theme) kozuka

 

Mei: Kou Yasuchika o kikou Natsuo with kao

 

 On the ura sidefs center, there is a five kanji mei gu no naka no soushinh cut with a chisel. The word soushin come from Chinese history, and concerns a story about piety for onefs parents, and this is included among the twenty four filial pieties. The main character, the crow, is described by ghanpo no kouh. This means that after a crow grows up, he never forget his obligations, and brings food to his parents. The bird is supposed to have a deep compassion between parents and child.

 Above the kanji characters, there is a signature gkou Yasuchika o kikouh. This means he modeled this after Yasuchikafs work. According to gKano Natsuofs Teacherfs Dictationsh published in Taisho 3 (1914), Yasuchika is a great master smith in Natsuofs opinion. He said in the book, g cbut beginners never understood him, so did not follow his works and study them, this is supposed to be a path for a beginner, but it is impossible to learn, so it is better not to begin to study his workh. This means that after you become experienced and skilled, then you should learn from him. From the signature and the kao, this is a Keio 2 (1866) period work, Natsuo was 39 years old at that time. After his mid-30s, Natsuo produced most of his work. Maybe he thought it was time for him to challenge and compete with Yasuchika, so these would be ambitious projects.

 From the overall composition and the clarity of the old treefs knots and leaves, you can see Yasuchikafs style, but at first impression, you can recognize Natsuofs work. You see his soft, rich, and well forged unique iron ground. The crowfs face is noble, and the small number of leaves around the tree are arranged with a delicate perspective, and give a depth and perspective to the entire scene. His flowing and elegant chisel marks and inlay work make it seem like he simply replaced a painterfs brush with a chisel, and this is different from Yasuchikafs use of high volume and texture. For something modeled after Yasuchikafs unique work, this is work by an artist who had established his own world and understood Yasuchikafs feelings, but expressed his own feeling with his own expert techniques. If an amateur goldsmith with no long history of work or experience tried to model his work after Yasuchikafs examples, his efforts would be a failure. Natsuofs words that gbeginners should never study himh indicates that he realizes this. For many years, I thought that Natsuofs work was just delightful, but from this work, I learned to really appreciate his art.

 

 

Explanation by Kubo Yasuko

 

 

 

Shijo Kantei To No. 722

 

The deadline to submit answers for the No. 722 issue Shijo Kantei To is April 5, 2017. 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, 2017 will be accepted. If there are sword smiths with the same name in different schools, please write the school or prefecture, and if the sword smith was active for more than one generation, please indicate a specific generation.

 

Information:

 

Type: tachi

 

Length: 2 shaku 4 sun 4.5 bu (74.1 cm)

Sori: 1 sun 6 rin (3.2 cm)

Motohaba: 9 bu 6 rin (2.9 cm)

Sakihaba: 6 bu 1 rin (1.85 cm)

Motokasane: 2 bu 1 rin (0. 65 cm)

Sakikasane: 1 bu 3 rin ( 0.4 cm)

Kissaki length: 9 bu 9 rin (3.0 cm)

Nakago length: 6 sun 8 bu (20.6 cm)

Nakago sori: slightly less than 7 rin (0.2 cm)

 

 This is a shinogi-zukuri tachi with an ihorimune and an almost standard width. The widths at the moto and saki are different. There is a large koshi-zori with funbari, the tip has sori, and overall, the tachi has a wa-zori-like shape and a chu-kissaki. The jihada is a tight ko-itame hada, there are fine ji-nie, some places have a unique appearing jifu in the ji, and there are bo-utsuri. The hamon and boshi are as seen in the picture. There are nijuba type yubashiri in some places, ashi, yo, a bright nioiguchi, frequent ko-nie, fine kinsuji and sunagshi, and muneyaki at the koshimoto. The nakago is ubu, and the nakago tip is kuri-jiri . The yasurime are kiri and there are two mekugi ana. On the omote side, above the second mekugi-ana (the original mekugi-ana) and towards the mune edge , there is a three kanji signature.

This smith has only a small number of works. Today we are only aware of about ten of his swords.

 

By Hinohara Dai 

 

 

 

Teirei Kanshou Kai For February, 2017 

 

The swords discussed below were shown in the February, 2017 meeting at the NBTHK headquarters building. This discussion presents answers concerning the makers of these blades.

Meeting Date: February 11, 2017 (2nd Saturday of February)

Place: Token Hakubutsukan auditorium

Lecturer: Ooi Takeshi

 

Kantei To No. 1: tachi

 

Mei: Masatsune

 

Length: 2 shaku 3 sun 3 bu 

Sori: 6.5 bu

Style: shinogi zukuri

Mune: ihorimune

Jihada: tight itame hada; some places show a visible hada. There are dense fine ji-nie and jifu utsuri.

Hamon: ko-midare and some places have gunome. There are frequent ashi and yo, a soft nioiguchi, strong nie, fine hotsure, kinsuji, and sunagashi; from the center to the yokote there are frequent yubashiri, and some places have nijuba; there is a worn down nioiguchi.  

Boshi: straight with frequent hakikake; the tip is sharp, and there is a small return.

 

 On many of Ko-Bizen Masatsunefs tachi the differences in the widths at the moto and saki are prominent, there is sakizori, and there is a classic shape. But his other shapes can have a relatively shallow sori, and because of this, the funbari and koshizori are not prominent. The Mino Ogaki clanfs Toda family tachi has a length of 2 shaku 5 sun 7 bu, and the sori is slightly less than 7 bu. There is another tachi, which before WWII was owned by the minister of agriculture Yamamoto Teisaburo, and later by the Manno museum. It has a length of 2 shaku 4 sun 5 bu 4 rin, and the sori is 6 bu 9 rin. Today, both of these tachi are owned by the Japanese government. This work belongs to this class of tachi. Because the bottom of the koshizori blade is suriage, at first impression it looks like the sori is strongest at the center (i.e. it is nakasori). However, some people realized that the funbari shape is gone, and originally, the tip was uchizori. Also, based on the ko-midare hamon, there are frequent nie, a classic hamon, and jifu utsuri. Many people recognized these chacteristic points, and voted for Ko-Bizen smiths.

In particular, because of the tight jihada, a large number of people voted for Masatsune. Some people voted for other Ko-Bizen smiths such as Tomomura, Naritaka, Yukihide, and Kageyasu, and if the emphasis was on the hamon, those answers are quite resonable.

 Some people guessed that the shape was Kyoto work, from regions with a small midare hamon with yubashiri, and they voted for Rai Kuniyuki, Awataguchi Kuniyasu, or Ayanokoji Sadatoshi. If it were their work, the utsuri would be mostly nie utsuri, a ko-gunome and ko-choji type hamon would be clearer and it would be  based on a suguha hamon, or a shallow midare hamon with clear valleys and high and low vertical variations. There would also be more Kyo saka-ashi in the hamon and a somewhat different feeling in the hamon.

 

 

 

Kantei To No. 2: wakizashi

 

Mei: oite Nanki Shigekuni tsukuru kore

Length: 1 shaku 2 sun 6 bu

Sori: slightly over 3 bu

Design: unokubi zukuri

Mune: ihorimune

Jihada: itame hada mixed with nagare hada and o-mokume hada, and the hada is just visible. There are dense ji-nie and thick chikei.

Hamon: based on a wide suguha; towards the tip, the hamon becomes wider; the upper part has continuous gunome and some choji. There are frequent ashi and yo, a dense nioiguchi, dense nie, some yubashiri and tobiyaki, nie-suji, kinsuji, sunagashi and a bright and clear nioiguchi.  

Boshi: midarekomi; there are frequent hakikake, nie kuzure, and the tip is yakizume.

 

This is a long, wide blade with a prominent sakizori, but compared with Muromachi period hira-zukuri wakizashi, it is thick and has a dynamic shape. From these details, the first choice would be for Keicho Shinto work.

 The jihada is a visible itame hada mixed with nagare hada, and along with the nagare hada, there are large elongated appearing mokume, and there are prominent chikei. The hamon has a dense nioiguchi, frequent nie, and towards the kissaki the hamon becomes wider. There are continuous gunome and choji and frequent hataraki in the hamon and on the edge of the hamon. In some places there are spiral-like kinsuji. On this sword, there are pale appearing kinsuji near monouchi. There are also some hakoba (square or box-like) shaped gunome. The boshi has strong and frequent hakikake, the tip is yakizume, and the shapes at the moto and ura are quite diffrent. The blade has a dynamic appearance and the details are bright and clear. 

 Shigekuni modeled his work after Go no Yoshihirofs work, and successfully mixed in influences from his familyfs traditional Yamato Den and Soshu Den styles which were very popular in that period. This wakizashi shows Nanki Shigekunifs charactereistic points in many places, and people with a thorough knowledge of his work easily reached the correct answer. Some people voted for other smiths because many of Shigekunifs wakizashi are hira-zukuri with mitsumune, and the inokubi-zukuri shape with an ihorimune appeared unusual for this smith. If you look at the overall work however, votes for other smiths seem to be a little unexpected.

 Some people voted for Kunimichi and Yasutsugu. Both of these smiths have sharp boshi. Kunimichifs hamon patterns have a prominent large scale midare hamon. If it were Yasutsugufs work, his nioiguchi are worn down, and if he made mokume-hada, large mokume are not prominent and his jigane have a dark colored steel typical of the Hokkoku (northern part of Japan).        

 

 

 

Kantei To No 3: wakizashi

 

Mei: Inoue Izumi-no-kami Kunisada with kiku mon

    Kanbun 10 nen(1670) 8 gatsu bi 

 

Length: 1 shaku 7 sun 4 bu

Sori: slightly less than 4 bu

Style: shinogi-zukuri

Mune: ihorimune

Jihada: tight ko-itame hada; there are thick dense ji-nie; some places show strong ji-nie; there are frequent fine chikei, and a bright and clear jihada.

Hamon: based on a suguha type hamon but some places are a shallow notare type hamon. There is a dense nioiguchi, frequent large round nie, some kuichigaiba, kinsuji, nie-suji and a bright and clear nioiguchi.

Boshi: straight, with frequent nie hakikake; the tip is sharp with a komaru; there is a long return which fades away.

 

  In the late Muromachi period, it become popular to wear a dai-sho (large and small pair) and people would choose blades depending on their individual heights and the practices of their individual kendo schools, and there seems to have been no strict standard size for wakizashi. But in Kanei 10 (1633), the Tokugawa bakufu forbade samurai from wearing wakizashi over 1 shaku 8 sun in length. After this, many smiths made mid-sized wakizashi which were less than 1 shaku 8 sun in length. Notably, wakizashi made around the Kambun period stand out.  

 This wakizashi with Shinkaifs Kunisada signature is less than 1 shaku 8 sun in length. The width, the widths at the moto and saki, and the thickness are standard. Compared with Muromachi period work, this has a shallow sori, saki-zori is not prominent, and considering the periodfs background, I would notice firstly, the Keicho Shinto shape.

 The jihada is a tight ko-itame, with a bright and clear refined jihada. In some places there are strong ji-nie, and at the koshimoto the hada is slightly visible which is one of Kunisadafs characteristic points. The hamon is bright and clear with a shallow notare type suguha. There are kinsuji, sunagashi, and the nioiguchi and nie are dense, so this work is obviously modeled after high class Soshu Den work. In particular, you can recognize Shinkaifs unique nie: they have a small size and appear like each one was carefully made by punching the steel with a small sharp tipped punch. Each nie particle is beautifully shaped.

 The prominent strong particulate-like nie like we see here in this wakizashi, is usually seen more often in his later work.

 The boshi is not a komaru sagari, and many wakizashi have a large return. The point to focus on here is the location where the return stops. It is not on the mune, but fades out on the shinoji-ji, and this is an important point.

 A fair number of people voted for Ippei Yasuyo. If it were his work, it would be thick with a large hira-niku and a strong shape. The jihada is ko-itame and other patterns, there would be a darker colored hada, and many of the nie particles have a crushed shape and overlap with each other. In addition, rough looking nie particles would be prominent.

 

 

 

Kantei To No 4: katana

 

 Mei: Sashu ju Hojoji Tachibana Yoshikuni

 

Length: 2 shaku 5 sun 5 rin

Sori: slightly less than 4 bu

Design: shinogi-zukuri

Mune: ihorimune

Jihada: itame hada, and the hada is visible. There are ji-nie, frequent chikei, a prominent clear jihada pattern, and a dark colored jihada. 

Hamon: there is a slightly wide hamon; it shows continuous ko-gunome, gunome, and a midare pattern. There are frequent ashi, nie, fine sunagashi and a bright nioiguchi.

Boshi: wide yakiba and straight; the omote tip is komaru with a long return, the ura tip is togari, there are some hakikake and a short return.

 

 Hojoji Yoshikuni worked around the Genroku to Hoei periods (1688-1710). He was the son of Nio Katakiyo, and later became Hojoji Yoshitsugufs adopted son, and they both moved to Satsuma. He supposed to have signed with the names Kunitake and Kunikiyo.

 The katanafs widths at the moto and saki are prominently different, there is a shallow sori, a short chu-kissaki, and this is a Kanbun Shinto shape. The jihada is slightly visible, and there is a continuous gunome midare hamon, which is a juzuba (string of beads) style midare hamon. From this, besides the Edo Hojoji school, many people voted for a smith whose work was similar to Kotetsufs work. 

 Because thereis not much of his work available to examine, all Hojoji school names were treated as a correct answer at this time. This is a juzuba style hamon, but it is based on a ko-gunome midare hamon, and the clarity of the nioiguchi is just slightly below that of Kotetsu, but the boshi is not a Kotestu style boshi. From this, many people looked at this as Hojoji school work: it is long, the jihada pattern is rich and shows excellent work, and from among the schoolfs smiths, people voted for the schoolfs top smith Omi no kami Masahiro. 

 But in examining small details, we see that their shapes are different. Masahiro and other Kambun shinto smiths who had saidan-mei, often had a low shinogi, and a low flat hiraniku. Conversely, this katanafs shape is thick with a wide shinogi ji, rich hiraniku, and a strong Satsuma like niku-oki (the bladefs ji is rounded and thick). Beside this, there is the dark jihada and prominent chikei, so some people narrowed their choices to the Satsuma related smith Yoshitsugu, and I admired their detailed sharp observations.

 Beside these, a fair number of people voted for Izumi no kami Kunisada and Kazusa no suke Kaneshige. Izumi no kami Kunisadafs notare hamon outline and individual gunome are larger, and many of them have a yakidashi at the moto. Kazusa no sukefs characteristic hamon are composed of gunome, and all of the gunome tops have an equal height, and this results in a resemblance of a suguha style. His midare hamon have repeat clusters or groupings of one and two gunome.

 

 

 

Kantei To No. 5: wakizashi

 

Mei: Nobukuni (Shodai)

 

Length: 1 shaku 2 sun 1.5 bu

Sori: 2 bu 

Design: hira-zukuri

Mune: ihorimune

Jihada: tight ko-itame, and on the ji near the hamon it is nagare hada. There are thick dense ji-nie, frequent fine chikei and bo-utsuri.

Hamon: shallow notare with some ko-gunome. There are ashi, frequent nie, some mura, small hotsure, some yubashiri, kinsuji, sunagashi and a bright nioiguchi.

Boshi: shallow notare style, with some hakikake; the tip on the omote is round; the tip on the ura is sharp; both sides have a standard return.

Horimono: on the omote and the ura there are katana-hi and tsure-hi carved through the nakago.  

     

This is wide, long, and thin for the width. There is a shallow sori, and the shape is a typical Enbun-Joji type hirazukuri wakizashi. The jihada is a tight ko-itame, there are thick dense ji-nie, frequent fine chikei, and utsuri. From this, you can decide the wakizashi is based on Yamashiro Den work. Besides this, near the hamon, the jihada is mixed with nagare hada, and this is Ryokai and Nobukunifs Yamato style-like characteristic point.    

 The hamon is based on a notare hamon mixed with gunome with frequent nie and a bright nioiguchi. There are yubashiri, kinsuji, and sunagashi, which is characteristic of Soshu Den, and especially of Sadamunefs style. The boshi is round with a komaru with hakikake. The horimono are katana hi with tsure hi, in a simple style, but with a feeling for horimono these can be seen to show the Shodai Nobukunifs characteristic points. The signature is under the mekugi-ana along the center, and made of large sized kanji carved with a fine chesel. The gnobuh kanji is slightly smaller than g kunih kanji, and on the left side, inside of the gkunih kanji the vertical line is slanted and you can recognize the Shodaifs characteristic signature.

 Looking at this as work of Nambokucho period Soshu Den smiths, some people voted for Sadamune and Rai Kunitsugu. Both smithsf jihada and hamon nie and chikei are more prominent, and most of Kunitsugufs sori are musori or very slight, and his hamon are wide for the bladefs width or mihaba. If it were Hasebe Kunishigefs work, it would be thinner, the jihada would be visible, and not only near the hamon, but also towards the mune side it would be masame. He also has large round boshi with a long return coming down to the machi.

 

 

 

 

 

 

 

 

 

 

Shijo Kantei To No. 720 (in the 2017 New Yearfs issue)

 

The answer for the Shijo Kantei To No. 720 in the New Yearfs

issue is a wakizashi by Soshu Hiromitsu.

 

This wakizashi is wide, long, and slightly thin for the width, and has a shallow sori. From the shape, you can judge this as work from the peak of the Nambokucho period.

 The nakago is short for the wakizashi, and this kind of shape is seen in tanto and hira-zukuri wakizashi in this period.

 Details seen in Hiromitsufs style are: (1) the jihada is itame mixed with mokume and the hada is visible, (2) there are ji-nie and frequent chikei, (3) the hamon is based on a choji and gunome midare hamon, (4) there are tobiyaki, yubashiri, and muneyaki which approaches a hitatsura effect, (5) there are dense nie, prominent kinsuji and sunagashi, and these details describe typical work from Soshu from the peak of the Nambokucho period. Hiromitsu rarely made any suguha hamon.

 Among hitatsura hamon, there is one style called gdango chojih which looks like kawazuko choji expanded even more towowards its sides. Hiromitsu has many hamon with this kind of prominent detail, and the hints referred to this.

 Hiromitsufs boshi are often parallel to the fukura, the hamon becomes wider towards the tip and is midare-komi. The tip is sharp and there is a long return.

 However Embun-Joji style tanto and hira-zukuri wakizashi have a characteristic point which is how thin they are. Actually, the Hasebe school, the Aoe school, and the Nambokucho period Hokke school all have work which is thin. But the Soshu smithsf Hiromitsu and Akihirofs works are thin but not excessivly thin.

 Hiromitsufs nakago tips are kurijiri, and his yasurime are katte-sagari. His signatures are mainly on the omote and along the center and consist of long mei. The ura side has a date. Sometimes we see two kanji signatures like this wakizashifs.

 In voting, majority of people voted for Hiromitsu. For an almost correct answer, a few people voted for Akimitsu.

 It is difficult to distinguish between Hiromitsufs and Akimitsufs work. Generally, Hiromitsufs hamon are mixed with dango-choji and a gorgeous midare hamon. Akimitsufs hitatsura hamon tend to be a smaller size, and sometimes contain togari.

 The majority of Hiromitsufs shapes are large, just like this wakizashi. Akimitsufs shapes are generally smaller, and this is one of the differences between their blades.

 Hiromitsufs dates are in the early Nambokucho period from Kano to Joji (1350-67). Akihirofs oldest date is Embun (1356-60), and continue into the latter half of the Nambokucho period from Joji, Oan, Eiwa, Koryaku, and Shitoku (1362-86). Consequently, their different styles may have resulted from changing shapes evolving through successive periods.

 

 

Explanation by Hinohara Dai