This antique Japanese katana, attributed to Gassan Sadayoshi, was made during the Tenpo era (1831-1845) of the late Edo period. It is unsigned (Ubu Mumei) and features the distinctive Ayasugi Hada, a signature design of the Gassan school. The blade comes with an NTHK Kanteisho Certificate, authenticating its attribution and period.
mumei · Gassan · Tenpo (1830-1844) · nagasa 80.4cm · sori 3cm













Shinshinto · Settsu · around 1830-1863
Fujishiro Jo saku · Tōken Taikan top 49%
1 piece on the market now
Shinshinto · Settsu
40 pieces on the market now
| Smith | Era | Designated |
|---|---|---|
| Sadaharu貞晴 | 1865-1868 | 0 |
| Sadayoshi貞吉 | 1926-1989 | 0 |
| Yoshiaki吉明 | 1844-1848 | 0 |
| Naonobu直信 | 1854-1860 | 0 |
| Sadayoshi貞吉 | 1830-1863 | 0 |
The NTHK’s principal certificate, issued for a blade of considerable quality. It confirms a genuine signature, or, for an unsigned (mumei) work, records the judges’ attribution to a smith or school. The paper carries a detailed worksheet with a numerical point score.
The NTHK (Nihon Tōken Hozon Kai, the Society for the Preservation of the Japanese Sword) is the oldest of Japan’s sword-appraisal bodies, founded in 1910, decades before the NBTHK. After the death of its long-serving head it divided into two successor societies, the NTHK and the NTHK-NPO, both of which continue to hold shinsa. NTHK certificates are known for a detailed worksheet that records a numerical point score alongside the judges’ written opinion, and the society is especially respected for its attribution of unsigned (mumei) work.
Returns/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, attributed to Gassan Sadayoshi, was made during the Tenpo era (1831-1845) of the late Edo period. It is unsigned (Ubu Mumei) and features the distinctive Ayasugi Hada, a signature design of the Gassan school. The blade comes with an NTHK Kanteisho Certificate, authenticating its attribution and period.
mumei · Gassan · Tenpo (1830-1844) · nagasa 80.4cm · sori 3cm













Shinshinto · Settsu · around 1830-1863
Fujishiro Jo saku · Tōken Taikan top 49%
1 piece on the market now
Shinshinto · Settsu
40 pieces on the market now
| Smith | Era | Designated |
|---|---|---|
| Sadaharu貞晴 | 1865-1868 | 0 |
| Sadayoshi貞吉 | 1926-1989 | 0 |
| Yoshiaki吉明 | 1844-1848 | 0 |
| Naonobu直信 | 1854-1860 | 0 |
| Sadayoshi貞吉 | 1830-1863 | 0 |
The NTHK’s principal certificate, issued for a blade of considerable quality. It confirms a genuine signature, or, for an unsigned (mumei) work, records the judges’ attribution to a smith or school. The paper carries a detailed worksheet with a numerical point score.
The NTHK (Nihon Tōken Hozon Kai, the Society for the Preservation of the Japanese Sword) is the oldest of Japan’s sword-appraisal bodies, founded in 1910, decades before the NBTHK. After the death of its long-serving head it divided into two successor societies, the NTHK and the NTHK-NPO, both of which continue to hold shinsa. NTHK certificates are known for a detailed worksheet that records a numerical point score alongside the judges’ written opinion, and the society is especially respected for its attribution of unsigned (mumei) work.
Returns/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.