Tachi〈Inscribed in Chugoku Sumiyoshi, October 2nd Year of

A Bitchū Blade Dated to the Autumn of 1346

The maker cut his name into one face of the blade in thin, deliberate chisel strokes: made by Tsugiyoshi, a resident of Bitchū Province, on a day in the tenth month of Jōwa 2. By the Western calendar that day fell in 1346, well into the Nanboku-chō period, when the country was divided between two rival imperial courts and fighting men carried longer, heavier swords than their grandfathers had owned.

The blade runs 81.5 centimeters along its cutting edge. It is shaped in shinogi-zukuri, the standard ridged cross-section, finished with a rounded back rather than the more usual peaked one. Look closely at the steel and the surface shows a fine ko-itame, a tight wood-grain pattern, while the tempering line follows a low, easy wave scattered with clusters that lean backward toward the hilt. Smiths call that backward-slanting clove shape saka-chōji, and it is one of the marks that point straight to Bitchū.

Tsugiyoshi worked within the Aoe school, the swordmaking lineage that grew up along the lower Takahashi River in what is now Okayama Prefecture. The name carried real weight. Of the dozen smiths Emperor Go-Toba is said to have summoned to forge under his own eye in the early thirteenth century, three came from Bitchū, and after the great centers of Yamashiro, Bizen, and Sagami, no province holds more nationally designated swords than this one.

The Aoe Lineage and Why This Sword Mattered

Scholars sort the Aoe smiths into three broad waves. The earliest, the Ko-Aoe of the late Heian and early Kamakura years, left blades of quiet, archaic grace. The middle group, the Chū-Aoe of the late Kamakura period, began the habit of cutting a date, a home district, or a court title into the signature, and they produced a steel famous for sumihada, a dark, streaky figure in the surface that pools like ink and appears in almost no other school. Tsugiyoshi belonged to the last wave, the Sue-Aoe of the Nanboku-chō age, who answered the taste of their violent century with broad, imposing tachi.

What made a sword like this worth preserving was not beauty alone but evidence. A blade carrying a clear, datable signature gives historians a fixed point. Undated works by the same hand or the same school can be measured against it, and the slow drift of a regional style across the fourteenth century becomes legible. The reverse clove pattern in the temper, the rounded back, the controlled wood-grain steel: each is a sentence in a record that the maker dated himself.

Recognizing that documentary value, the Japanese government designated the sword an Important Cultural Property on the second day of February in 1955. It was then in private hands in Tokyo, and it came with its own dressing, an itomaki-tachi koshirae, the silk-wrapped court mounting in which a tachi of this rank would have hung at the hip.

A Sword Now Lost to View

There is a hard fact to record here. This blade is no longer where the record can find it.

The Agency for Cultural Affairs lists the Tsugiyoshi tachi among the nationally designated treasures whose whereabouts have become unknown. A designated work in private ownership can change hands, move quietly between collections, or simply drop out of contact with the authorities over the decades, and at some point the trail on this one went cold. The agency keeps a public register of such objects and asks anyone who recognizes them to make contact, in the hope that they resurface intact rather than being broken up, exported without papers, or lost outright.

For a visitor, that means there is no museum case to stand in front of and no opening hours to check. What survives in public is the description, the measurements, and a single archival photograph held by the agency. It is worth carrying that knowledge lightly when you handle any old blade or inherit an unfamiliar one: a sword that looks like a curiosity in a family storehouse can, on occasion, turn out to be a registered cultural property that the country has been trying to locate.

Where to See Aoe Swords Today

Although this particular tachi cannot be visited, the Aoe tradition it represents is well within reach, and the best single place to meet it is the Tokyo National Museum in Ueno Park. The museum holds several Aoe blades across the school's phases, including an Important Cultural Property tachi by the Chū-Aoe smith Yoshitsugu, dated 1330 and once presented to Emperor Meiji by the Mōri family, along with works attributed to the older Ko-Aoe masters.

Swords rotate through the galleries rather than staying on permanent view, so the specific blade on display changes through the year. Check the museum's online collection listings before you travel to see which Bitchū works are out. Standing in front of a Chū-Aoe blade gives you the closest honest sense of what the Tsugiyoshi sword would have shown: the sumihada figure in the steel, the slanting clove temper, the long Nanboku-chō silhouette. For deeper study, the Japanese Sword Museum in Sumida and the catalogues of e-Kokuhō, the national museums' online archive, both gather Aoe material in one place.