Tachi (unsigned, Ichimonji school; known as Yamatorige)

A Kamakura Tachi of the Ichimonji School, National Treasure since 1952

Tachi (unsigned, Ichimonji school; known as Yamatorige) (太刀〈無銘一文字（山鳥毛）〉) is a Kamakura-period long sword held by the Bizen Osafune Japanese Sword Museum in Setouchi City, Okayama Prefecture, designated a National Treasure in 1952, on 29 March. It had become an Important Cultural Property on 3 May 1940. The quantity is one sword, the category applied arts, and the designation number 00044. It belongs to the city of Setouchi.

The Agency for Cultural Affairs writes: a work standing with the Nikko Ichimonji, this tachi displays to the full the manner and the force of the Bizen Ichimonji school at its height. Its temper line is the most boldly patterned, rich in variation within the edge. It descended in the Uesugi family as a favoured sword of Uesugi Kenshin and Kagekatsu.

Ichimonji is not a smith's name but the name of a body of smiths based at Fukuoka in Bizen province. Unsigned means no signature was cut, so no individual maker is identified. The name records a school rather than a person.

The sobriquet is read two ways, Yamatorige and Sanchomo. The Agency's reading is Yamatorige; the prefectural record gives Sanchomo.

The Origin of the Name Is Not Clear

Of the sobriquet the Agency writes: one account holds that the temper line resembles the plumage of a mountain bird, but other accounts exist and the matter is not clear.

The plumage explanation is widely repeated, but the Agency states plainly that other accounts exist and that the question is unsettled. This article does not present it as established.

A sobriquet is a name given to a particular blade, often descending through tradition. That the sword is unsigned and that the origin of its name is unsettled both point to gaps in what is known of its history.

Dimensions: The Records Differ

Accounts of the measurements do not agree.

The Agency's national cultural properties database gives a blade length of 79.1 centimetres, a curvature of 3.3 centimetres, a width of 3.5 centimetres at the base and 2.2 at the tip, and a point 3.3 centimetres long. Okayama Prefecture gives a blade length of 71.2 centimetres and a curvature of 2.7 centimetres.

The blade lengths differ by about eight centimetres. The digits of 79.1 and 71.2 are close in order, so one may be a transcription error, but that cannot be confirmed. This article follows the Agency's figures and notes the discrepancy.

The Agency describes the blade as ridged in section with a pitched back, the point short and stubby, the curvature high toward the hilt, with good taper. The forging is a wood-grain pattern with a faint undulating reflection.

A short stubby point and a curvature centred toward the hilt are both marks of a mid-Kamakura tachi.

From the Uesugi to the City of Setouchi

The sword descended in the Uesugi family as a favoured blade of Uesugi Kenshin and Kagekatsu, and appears in an inventory written by Kagekatsu himself.

Ownership later changed hands, and for a time it was deposited at the Okayama Prefectural Museum. In 2018 Setouchi City launched a project to acquire it, raising funds through hometown-tax crowdfunding and corporate hometown-tax donations. About 500 million yen was gathered, and on 22 March 2020 the sword became the property of the city.

Fukuoka in Bizen, where it was made, lies within present-day Setouchi City. The work of a body of smiths returned to the ground on which they worked.

Seeing It: About Once a Year

The Bizen Osafune Japanese Sword Museum holds the sword, but it is not on permanent display. Setouchi City states that it is shown about once a year.

The timing varies by year, and the sword is sometimes lent elsewhere; in 2025 it was shown at the Joetsu City History Museum in Niigata Prefecture. Check the city's or the museum's information for the display schedule before travelling.

The museum shows swords with an emphasis on Bizen work. A forge on the grounds allows visitors to watch traditional forging on certain days. Booking may be required, so check that as well.

From Osafune Station on the JR Ako Line it is about seven minutes by car, or about 20 minutes on foot from Kagato Station. From the Tenno or Funayama stops on the Uno bus it is about ten minutes on foot.