This antique Japanese Tanto is signed by Minamoto Masao, a top-tier swordsmith from the end of the Edo period (1853-1866). Masao was the best apprentice of the renowned Minamoto Kiyomaro and sometimes signed on his master's behalf, making his own signed works rare. The blade comes with an NBTHK Hozon Certificate, koshirae, and shirasaya.
mei · Koka (1844-1848) · nagasa 13.7cm


























Shinshinto · Musashi · around 1844-1857
Fujishiro Jo-jo saku · Tōken Taikan top 31%
3 pieces on the market now
Yamaura Masao was born in Bunka 1 (1804) in Akaiwa village, Komoro, Shinano Province, the eldest son of the rural samurai Yamaura Nobukaze and elder brother of the celebrated Kiyomaro. Together with Kiyomaro, he studied under the Ueda domain smith Kawamura Toshitaka, signing early works as Kanri and Toshimasa before adopting the name Masao, then Shin'o, and finally Toshinaga in his later years. He used art names including "Tennenshi," "Yushaken," and "Yuunsai," and died in Meiji 7 (1874) at seventy-one.
His stylistic trajectory followed that of his brother: beginning with choji in the manner of Toshitaka, then shifting decisively toward Soshu-den. The setsumei consistently note a forging of itame-hada with thick ji-nie and conspicuous chikei, and a tempering of gunome mixed with ko-notare, richly laden with nie, kinsuji, and sunagashi. His finest katana (Juyo, 58th Session) is described as possessing "a powerful forging -- thick with ji-nie and heavily interwoven with chikei" in which "kinsuji and sunagashi activities are richer than usual even for this maker's work." Yet the NBTHK observes that "in comparison with Kiyomaro, his work tends to show fewer chikei in the ji and fewer sunagashi and kinsuji within the hardened area, and the overall quality does not reach Kiyomaro's level."
Despite this candid assessment, Masao's designated works demonstrate a smith of real accomplishment, particularly in the Soshu-den mode where nie is vigorously expressed and his shobuzukuri wakizashi display the sharp fukura-kare profile he favored. His output spans both katana of bold construction and wakizashi of refined character, and his commissions from named patrons attest to the regard in which he was held during the shinshinto era.
Where Masao stands among comparable artisans: across all of nihontō, and within tradition, era, and period. The tiers (Foremost · Leading · Major · Notable) weigh official designations from the NBTHK and Japan's Agency for Cultural Affairs, together with historical honors of lasting repute such as the Sansaku and Meibutsu-chō.
Select a lens to see how it's measured.
Years he was demonstrably active, proven by signed-and-dated blades
Shinshinto · Musashi
13 pieces on the market now
The Kiyomaro school gathered in the workshops of Yotsuya in Edo around the middle of the nineteenth century, its founder Yamaura Kiyomaro (清麿) born in Bunka 10 (1813) at Akaiwa village in the Komoro district of Shinano, the second son of the country gentry-warrior Yamaura Nobukaze. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Kiyomaro清麿 | 1839-1854 | 52 |
| Nobuhide信秀 | 1857-1867 | 34 |
| Kiyondo清人 | 1848-1868 | 8 |
| Masao真雄 | 1844-1866 | 6 |
| Masanao正直 | 1865-1868 | 3 |
Certifies a genuine blade worth preserving: a signature confirmed correct, or, if unsigned, an era, province, and school that the NBTHK can reliably identify.
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 Tanto is signed by Minamoto Masao, a top-tier swordsmith from the end of the Edo period (1853-1866). Masao was the best apprentice of the renowned Minamoto Kiyomaro and sometimes signed on his master's behalf, making his own signed works rare. The blade comes with an NBTHK Hozon Certificate, koshirae, and shirasaya.
mei · Koka (1844-1848) · nagasa 13.7cm


























Shinshinto · Musashi · around 1844-1857
Fujishiro Jo-jo saku · Tōken Taikan top 31%
3 pieces on the market now
Yamaura Masao was born in Bunka 1 (1804) in Akaiwa village, Komoro, Shinano Province, the eldest son of the rural samurai Yamaura Nobukaze and elder brother of the celebrated Kiyomaro. Together with Kiyomaro, he studied under the Ueda domain smith Kawamura Toshitaka, signing early works as Kanri and Toshimasa before adopting the name Masao, then Shin'o, and finally Toshinaga in his later years. He used art names including "Tennenshi," "Yushaken," and "Yuunsai," and died in Meiji 7 (1874) at seventy-one.
His stylistic trajectory followed that of his brother: beginning with choji in the manner of Toshitaka, then shifting decisively toward Soshu-den. The setsumei consistently note a forging of itame-hada with thick ji-nie and conspicuous chikei, and a tempering of gunome mixed with ko-notare, richly laden with nie, kinsuji, and sunagashi. His finest katana (Juyo, 58th Session) is described as possessing "a powerful forging -- thick with ji-nie and heavily interwoven with chikei" in which "kinsuji and sunagashi activities are richer than usual even for this maker's work." Yet the NBTHK observes that "in comparison with Kiyomaro, his work tends to show fewer chikei in the ji and fewer sunagashi and kinsuji within the hardened area, and the overall quality does not reach Kiyomaro's level."
Despite this candid assessment, Masao's designated works demonstrate a smith of real accomplishment, particularly in the Soshu-den mode where nie is vigorously expressed and his shobuzukuri wakizashi display the sharp fukura-kare profile he favored. His output spans both katana of bold construction and wakizashi of refined character, and his commissions from named patrons attest to the regard in which he was held during the shinshinto era.
Where Masao stands among comparable artisans: across all of nihontō, and within tradition, era, and period. The tiers (Foremost · Leading · Major · Notable) weigh official designations from the NBTHK and Japan's Agency for Cultural Affairs, together with historical honors of lasting repute such as the Sansaku and Meibutsu-chō.
Select a lens to see how it's measured.
Years he was demonstrably active, proven by signed-and-dated blades
Shinshinto · Musashi
13 pieces on the market now
The Kiyomaro school gathered in the workshops of Yotsuya in Edo around the middle of the nineteenth century, its founder Yamaura Kiyomaro (清麿) born in Bunka 10 (1813) at Akaiwa village in the Komoro district of Shinano, the second son of the country gentry-warrior Yamaura Nobukaze. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Kiyomaro清麿 | 1839-1854 | 52 |
| Nobuhide信秀 | 1857-1867 | 34 |
| Kiyondo清人 | 1848-1868 | 8 |
| Masao真雄 | 1844-1866 | 6 |
| Masanao正直 | 1865-1868 | 3 |
Certifies a genuine blade worth preserving: a signature confirmed correct, or, if unsigned, an era, province, and school that the NBTHK can reliably identify.
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.