Katana Mumei, Sa Hiroyuki

NBTHK Jūyō Tōken

Mid Nanbokuchō Period (1333-1392), circa 1350

Nagasa [length]: 73.6 cm

Sori [curvature]: 1.9 cm

Motohaba [bottom width]: 3.1 cm

Sakihaba [top width]: 2.5 cm

Motokasane [bottom thickness]: 6.8 mm

Sugata [configuration]: Shinogi-zukuri, iori-mune, wide mihaba on the whole blade, light sori, ō-kissaki (9.9 cm)

Kitae [forging pattern]: Itame hada mixed with mokume, which sometime turns to ko-itame and nagare. Thick jinie, many chikei, some shirake-gokoro and some golden areas.

Hamon [tempering pattern]: Shallow notare based on suguha, gunome, ko-notare, mixed to togariba. Ashi, yō, deep nioi and thick ko-nie, some ara-i, uchi-no-ke, yubashiri, sunagashi and kinsuji in the nioiguchi.

Boshi [point]: Midarekomi on omote side, which turns to togarigokoro and rich hakikake. On ura side slight notarekomi turning to ko-maru.

Nakago [tang]: O-suriage, sakikiri; three mekugi-ana (two filled).

Horimono [carving]: Bo-hi on omote and futatsui-hi on ura.

Origami [paper]: The blade comes with a Jūyō Tōken (Important Sword) certificate issued by the Nihon Bijutsu Token Hozon Kyokai in 2016 (62nd session). 

Sayagaki [certification on shirasaya]: The inscription by Tanobe sensei reads: 

“Chikuzen Kuni Sa Hiroyuki - Suriage mumei; polished. The blade shows the strong shape and the style of the Nanbokucho period, around the Enbun or Joji era. Forging is exquisite, with deep nie ko-notare and gunome midare hamon. The blade is typical from the Samonji school, with a powerful design and a clear colour. Blade length ~ 73.6 cm. Written by Tanzan (Tanobe) Michihiro+kao”

Samonji, whose real name was Saemon Saburo Yasuyoshi, is considered one of the top swordsmiths of all times; he is also known with the nickname of “Ō-Sa”, meaning “The Great Sa”, since he used the kanji “Sa” (左) to sign his swords. Samonji worked in Chikuzen, in the Kyūshū island, but he broke up with the local tradition around 1340-50 and switched to the Sōshū style, founded in Kamakura by Shintogo Kunimitsu and perfected by Masamune, Yukimitsu and Norishige. That means he used more nie-based hataraki like kinsuji and sunagashi, with the hamon that became notare mixed with gunome.

Samonji was also an active teacher, with several students. Out of all of them, Yukihiro is probably the first one and for sure the closest to his teacher. Yukihiro had a son who also became Sa’s student, Hiroyuki, the sword-smith who this blade is attributed to. Sa Hiroyuki followed his master’s style, with the use of a beautiful flowing hadatachi itame hada, as on this blade. The boshi is treated with attention, here with two different styles, with the long Kaeri introduced by Sa. The Japanese government has designated some of Hiroyuki's blades as "Important Cultural Property," and among them is a tanto dated 1350, which helps to date his work. 

The sugata of this katana, with the predominance of an imposing kissaki, is quite typical of the Nanbokuchō period, which saw bitter internal struggles and was marked by a climate of virile ostentation both in the context of the opposition of the northern and southern courts, and in anticipation of a feared third Mongol invasion. The conflict between the two courts lasted for more than half a century and as a result brought about an increase for the demand of swords as weapons. Kyūshū served as a stage for the intense confrontation between both armies and Chikuzen was in fact the seat of governance for the area. It is thought that Samoji and his school supplied swords to Noriuji and Naoji Isshiki of the Kyūshū Tandai, and the Chikuzen Shoni (Military Commissioners). Those blades have been the longest of all time, with a massive shape and a pronounced kissaki, so that they could be repaired in case they were damaged during battle.