A Ko-Bizen Tachi Offered to Itsukushima
The Sword (Made by Tomonari) (太刀〈銘友成作〉) is a tachi made in the Heian period by Tomonari of the Ko-Bizen school, held by Itsukushima Shrine in Miyajima-cho, Hatsukaichi City, Hiroshima Prefecture, and designated a National Treasure on November 22, 1952. It had first been designated under earlier law in 1914.
The Agency for Cultural Affairs records a blade length of 79.4 centimetres, a curvature of 3.0 centimetres, a width of 3.0 centimetres at the base and 1.9 centimetres at the tip, a point length of 2.9 centimetres and a tang of 19.7 centimetres. The tang is unshortened and bears a large three-character signature, Tomonari saku. The Itsukushima Zue calls it the tachi of Taira no Munemori, while shrine tradition holds that it was the sword of Taira no Noritsune, governor of Noto, offered to the shrine.
Why It Is a National Treasure
According to the Agency, several smiths seem to have used the name Tomonari from around the Eien era of the late 10th century into the Kamakura period. This blade's temper line is not the small irregular pattern typical of Ko-Bizen but is based on a straight line with a slightly tight edge, so it is thought to be a somewhat later work among those signed Tomonari.
The Agency praises its fine state of preservation and the excellent quality of its steel and temper line. That its tang survives unshortened, preserving the sword's original form, adds further to its value.
What to Look For
Look first at the shape: a high curve near the hilt with a strong, planted base, and grooves (bohi) running along both faces, as the Agency describes. The steel is tightly forged in a fine grain with delicate crystals and a faint clouded reflection.
The temper line is a medium straight line with a gentle undulation, mixed with small irregularities and many small choji legs; on the front a large burst of temper (koshiba) appears near the base, and the edge is tight overall with fine crystals. Try to pick out each of these features on the blade itself.
Seeing the Sword
Itsukushima Shrine holds some 260 items, each designated as a National Treasure or an Important Cultural Property, part of which is displayed in its treasure hall, according to the Miyajima Tourist Association. Displays rotate, so ask the shrine whether a particular piece is on view.
According to the shrine's official information, the treasure hall is open year-round from 8:00 a.m. to 5:00 p.m., with admission of ¥300 for adults, ¥200 for high school students and ¥100 for junior high and elementary school students. A combined ticket with the shrine buildings (¥500 for adults) is sold at the shrine entrance. The treasure hall is at 1162-18 Miyajima-cho, Hatsukaichi City, Hiroshima Prefecture; enquiries go to Itsukushima Shrine (0829-44-2020).
Q&A
- How big is the Tomonari tachi?
- The Agency for Cultural Affairs records a blade of 79.4 centimetres with 3.0 centimetres of curvature and a tang of 19.7 centimetres.
- When was it designated a National Treasure?
- On November 22, 1952.
- Who was Tomonari?
- A Ko-Bizen swordsmith; several smiths seem to have used the name from the late 10th century into the Kamakura period.
- Who is said to have offered this tachi?
- The Itsukushima Zue calls it the sword of Taira no Munemori, while shrine tradition says it belonged to Taira no Noritsune.
- Where can I see the Tomonari tachi?
- It may be shown in Itsukushima Shrine's treasure hall; displays rotate, so check with the shrine.
Basic Information
| Name | Sword (Made by Tomonari) (太刀〈銘友成作〉) |
|---|---|
| Location | 1-1 Miyajima-cho, Hatsukaichi City, Hiroshima Prefecture (Itsukushima Shrine) |
| Designation | National Treasure (Fine Arts and Crafts: Crafts) |
| Year Designated | National Treasure 1952/11/22 (Showa 27); earlier designation 1914/4/17 (Taisho 3) |
| Quantity | 1 sword |
| Dimensions | Blade length 79.4 centimetres, curvature 3.0 centimetres, tang length 19.7 centimetres |
| Owner | Itsukushima Shrine |
| Public Access | May be shown in the treasure hall (displays rotate) |
References
- 太刀〈銘友成作／〉 (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/bsys/maindetails/201/376
- Treasure hall (Miyajima Tourist Association)
- https://www.miyajima.or.jp/sightseeing/ss_homotsukan.html
Last verified: 2026.10.04