This antique Japanese katana is attributed to the Ko-Uda school by the NBTHK, dating it to the Kamakura-Nanbokucho period (approx. 1299-1393). The blade comes with a Tokubetsu Hozon Certificate, shirasaya, and a complete koshirae featuring a Tōjin-zu fuchi-kashira, Hanaguruma menuki, and an iron tsuba with pine tree and sailing vessel design. It is a well-preserved example of a practical blade from a tumultuous period in Japanese history.
Certificate reading — 無銘(古宇多)
mumei · Uda · Nanbokucho · nagasa 67cm · sori 1.8cm



























Wakimono · Etchu
Phase: Ko-Uda古宇多· 1310–1394
6 pieces on the market now
Ko-Uda (古宇多) names the founding stratum of the Uda school, the work that does not descend later than the Nanbokucho period and so stands before the long Muromachi continuation that the same studio names would carry. The setsumei place the origin in Yamato: around the Bunpo era at the close of Kamakura, the monk-smith Ko-nyudo Kunimitsu left Uda District in Yamato and settled at Utsu in Etchu, and from him the lineage took root. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Ko-Uda古宇多 | 1310-1360 | 50 |
| Kunifusa國房 | 1368-1375 | 17 |
| Kunimitsu國光 | 1362-1368 | 9 |
| Tomonori友則 | 1390-1394 | 4 |
| Kunitsugu國次 | 1356-1361 | 1 |
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 siteReturns/exchanges limited to defects caused by shipping (except willful misconduct or gross negligence by the company); customers must contact within 72 hours of receiving the product.
This antique Japanese katana is attributed to the Ko-Uda school by the NBTHK, dating it to the Kamakura-Nanbokucho period (approx. 1299-1393). The blade comes with a Tokubetsu Hozon Certificate, shirasaya, and a complete koshirae featuring a Tōjin-zu fuchi-kashira, Hanaguruma menuki, and an iron tsuba with pine tree and sailing vessel design. It is a well-preserved example of a practical blade from a tumultuous period in Japanese history.
Certificate reading — 無銘(古宇多)
mumei · Uda · Nanbokucho · nagasa 67cm · sori 1.8cm



























Wakimono · Etchu
Phase: Ko-Uda古宇多· 1310–1394
6 pieces on the market now
Ko-Uda (古宇多) names the founding stratum of the Uda school, the work that does not descend later than the Nanbokucho period and so stands before the long Muromachi continuation that the same studio names would carry. The setsumei place the origin in Yamato: around the Bunpo era at the close of Kamakura, the monk-smith Ko-nyudo Kunimitsu left Uda District in Yamato and settled at Utsu in Etchu, and from him the lineage took root. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Ko-Uda古宇多 | 1310-1360 | 50 |
| Kunifusa國房 | 1368-1375 | 17 |
| Kunimitsu國光 | 1362-1368 | 9 |
| Tomonori友則 | 1390-1394 | 4 |
| Kunitsugu國次 | 1356-1361 | 1 |
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 siteReturns/exchanges limited to defects caused by shipping (except willful misconduct or gross negligence by the company); customers must contact within 72 hours of receiving the product.