The red circle above indicates the time we discuss in this section
It is said that the first sword-making started from Yamato province (present Nara prefecture) during the Nara period (710 to 794). In the early sword-making days, their forging techniques were primitive. At that time, a large number of swordsmiths lived in Yamato, yet as time passed, the sword making declined in this area.
At the end of the Kamakura period, several powerful Buddhist temples in the Yamato area had power struggles against each other. Temples had a strong political and military power to control a large territory called Shoen (荘園) with their large number of warrior monks called Sohei (僧兵). The most powerful group was called Nanto Sohei (南都僧兵)*. The groups of Sohei demanded more swords to arm themselves. The high demand for swords from Sohei revitalized the Yamato Den (school) and increased the number of swordsmiths in the Yamato area. As a result, Yamato Den became active again. The Yamato Den style is somewhat similar to that of Yamashiro Den.
*Nanto Sohei (南都僧兵)———Since around the 11th century, Buddhist temples had become powerful under the protection from the Jokos (retired emperors). Those temples had a large number of Sohei (low-level monks who also acted as soldiers). When power struggles started between the temples, Sohei fought as their soldiers on the battlefields. Nanto Sohei were such soldiers at Kofuku-Ji Temple (興福寺). Several large temples such as Todai-Ji (東大寺) Temple controlled the Yamato area.
Sugata (姿: Shape) —————- Not much difference in style at the early part of Yamato Den and Yamashiro Den. Shinogi is high. Mune is thin. Some types of Yamato Den have shallow sori (curvature).
Hamon (刃文：Tempered line) ——————–Narrow tempered line. Mainly Nie (沸). Chu-suguha-hotsure (中直刃ほつれ: a medium straight line with a frayed pattern), Ko-choji-midare (小丁子: a mixture of small clove-like pattern and irregular wavy lines), Ko-midare (小乱: fine irregular wavy lines), Ko-gunome-komidare (小五の目小乱: small continuous half-circles mixed with wavy lines).
The main characteristic of the Yamato Den style sword is Masame (straight grain). Their tempered line often shows Nijyu-ha (double straight lines), Hakikake (tracing of a broom mark), Uchinoke (a crescent-shape line), or combinations of them. See the illustration below.
Boshi (鋩子: Tempered line at Kissaki area)———-On the Boshi area, a straight grain Hamon pattern appears. Yakizume or Kaen. (Refer Chapter 12 Middle Kamakura period: Tanto). O-maru, Ko-maru, Nie-kuzure. (Refer 14| Late Kamakura Period: Sword (鎌倉末太刀). See the illustration below.
Jihada or Jitetsu (the area between Shinogi and Hamon )——Mostly Masame–hada (straight grain pattern 柾目肌). Fine ji-nie, Chikei, and Yubashiri shows (refer 14 Late Kamakura Period).
Nakago (Hilt)——————Often shows the finishing file pattern as shown below. This is called Higaki Yasuri (檜垣).
Names of the Yamato School Sword-smiths
Taema(当麻) Group————–Taema Kuniyuki(当麻国行) Taema Tomokiyo(当麻友清) Shikkake (尻懸) Group———————————————–Shikkake Norinaga (尻懸則長) Tegai (手掻) group —————–Tegai Kanenaga (手掻包永) Tegai Kanekiyo(手掻包清) Hoshou (保昌) group——–Hosho Sadayoshi ( 保昌貞吉) Hosho Sadamune (保昌貞宗)
Yamato Senjuin Saya Enso (大和千手院沙弥円宗) once my family sword
Study of Japanese Sword 