This is a Kamakura period katana by the Ko-Mihara school, founded by Masaie, and comes mounted in koshirae. The blade exhibits strong Yamato and some Bizen influences, characteristic of the school located in Bingo Province. It is accompanied by an NBTHK Tokubetsu Hozon Certificate.
Certificate reading — 無銘(古三原)
mumei · Ko-Mihara · Kamakura












Yamato-den · Bingo
12 pieces on the market now
Bingo province, and the town of Mihara on the Numata river within it, gives this school its name. The Mihara group arose at the close of the Kamakura period and worked on through the Nanbokucho years, and the published sources gather the work of that early phase under the collective name Ko-Mihara, reserving Sue-Mihara for the late-Muromachi continuation of the line. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Masahiro正廣 | 1362-1389 | 33 |
| Masaie正家 | 1353-1375 | 29 |
| Sukekuni助國 | 1321-1329 | 23 |
| Kaneyasu兼安 | 1352-1369 | 12 |
| Masanobu正信 | 1376-1394 | 4 |
A Hozon-certified blade judged to show notably superior workmanship and a better state of preservation. The bar is higher: re-tempered blades and most unsigned Muromachi/Edo works are excluded.
The NBTHK (Nihon Bijutsu Tōken Hozon Kyōkai, the Society for the Preservation of Japanese Art Swords) is a public-interest incorporated foundation founded in 1948 and supervised by Japan’s Agency for Cultural Affairs (Bunkachō); it is based at the Japanese Sword Museum in Tokyo. Its expert panels physically examine each submitted work (shinsa) and issue a certificate (kanteishō) ranking it by artistic and historical merit. NBTHK papers are the most widely recognized standard of authentication for Japanese swords and fittings.
NBTHK official siteThis is a Kamakura period katana by the Ko-Mihara school, founded by Masaie, and comes mounted in koshirae. The blade exhibits strong Yamato and some Bizen influences, characteristic of the school located in Bingo Province. It is accompanied by an NBTHK Tokubetsu Hozon Certificate.
Certificate reading — 無銘(古三原)
mumei · Ko-Mihara · Kamakura












Yamato-den · Bingo
12 pieces on the market now
Bingo province, and the town of Mihara on the Numata river within it, gives this school its name. The Mihara group arose at the close of the Kamakura period and worked on through the Nanbokucho years, and the published sources gather the work of that early phase under the collective name Ko-Mihara, reserving Sue-Mihara for the late-Muromachi continuation of the line. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Masahiro正廣 | 1362-1389 | 33 |
| Masaie正家 | 1353-1375 | 29 |
| Sukekuni助國 | 1321-1329 | 23 |
| Kaneyasu兼安 | 1352-1369 | 12 |
| Masanobu正信 | 1376-1394 | 4 |
A Hozon-certified blade judged to show notably superior workmanship and a better state of preservation. The bar is higher: re-tempered blades and most unsigned Muromachi/Edo works are excluded.
The NBTHK (Nihon Bijutsu Tōken Hozon Kyōkai, the Society for the Preservation of Japanese Art Swords) is a public-interest incorporated foundation founded in 1948 and supervised by Japan’s Agency for Cultural Affairs (Bunkachō); it is based at the Japanese Sword Museum in Tokyo. Its expert panels physically examine each submitted work (shinsa) and issue a certificate (kanteishō) ranking it by artistic and historical merit. NBTHK papers are the most widely recognized standard of authentication for Japanese swords and fittings.
NBTHK official site