Muromachi turned sword making into an industry: the uchigatana rose with massed infantry warfare, Osafune and Seki produced bundle swords beside custom orders, and the Ming trade carried Japanese blades abroad by the tens of thousands.
This is a Koto period tanto by Gassan, a rare signed example from the Muromachi period. It features a fine suguha hamon and the distinctive ayasugi-hada, a specialty of the Gassan school. The tanto comes with a luxurious aikuchi koshirae, decorated with black lacquer, vermilion cloud motifs, and silver fittings depicting waves.




Wakimono · Dewa · around 1394-1428
Tōken Taikan top 60%
2 pieces on the market now
Where Gassan 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.
Wakimono · Dewa
52 pieces on the market now
Mount Gassan rises among the Dewa Sanzan, the three sacred peaks of northern Japan bound to the mountain asceticism of Shugendō, and the swordsmiths who took the mountain's name worked in its shadow in Ōshū, Dewa Province. The setsumei record that smiths signing "Gassan" are noted in the Kanchiin-bon Meizukushi as early as the Heian period, and the lineage's oldest surviving signed blade is a tachi simply signed Gassan, kept at the Gassan Shrine and judged to date from the late Nanbokuchō to early Muromachi period. Around that same early Nanbokuchō moment the corpus places Gassan Nagamitsu, whose signed tachi answers to the "Ushū Gassan group, around the Ryakuō era" recorded in the Meikan, and Shōgun, a Nanbokuchō hand sometimes identified with Gunshō, dated Genchū 3 (1386). A later branch is carried by Gassan Chikanori, working into the mid and late Muromachi (an ubu wakizashi dated Eishō 9, 1512). The line was revived in Osaka in the closing Tokugawa and Meiji years by Gassan Sadayoshi and his adopted son Gassan Sadakazu, who endured the Haitōrei edict and was appointed Teishitsu Gigei-in (Artist to the Imperial Household) in Meiji 39; his own adopted son Gassan Sadaichi continued the title into Taishō. The forging is the school's signature. " Over the itame base the grain flows (nagare) and tends to stand; ji-nie adheres and chikei enter, and the northern steel takes a dark, metal-like (kana-iro) hue read as Ōshū temperament.
The temper of the old line is a suguha whose nioiguchi is shizumi (subdued), at times mixed with gunome and ko-midare and softened toward urumi, the bōshi turning back in ko-maru. Departures within the corpus mark the lineage's range: Chikanori's late work can drop the ayasugi entirely and absorb Sue-Bizen and Osafune manners, while the Osaka revival smiths command itame with thick ji-nie, flamboyant nie-laden midare, kinsuji, and sunagashi in a full Sōshū idiom, and both Sadakazu and Sadaichi added meticulous horimono, from Bishamonten kurikara to taki kaen Fudō and dragon carvings carved by the same hand that forged the blade. For recognition the setsumei point first to the wave-grain ayasugi and the subdued, often slightly urumi northern nioiguchi, and where these recede, to the dark steel and standing grain that still betray an Ōshū hand. Signed examples of the old line are described as extremely rare, which raises the documentary weight of Nagamitsu's tachi and Shōgun's dated tantō. Provenance threads through the school's own sanctuary: the founding tachi and an Important Art Object tachi both reside at the Dewa Sanzan and Gassan Shrines. The Osaka revival is anchored in the Imperial collection, where Sadaichi tantō signed Teishitsu Gigeiin survive, alongside a Sadakazu wakizashi made on commission for Prince Kuni. Across six centuries the setsumei track a single mountain workshop, from the subdued ayasugi of the Dewa founders through a Muromachi offshoot that turned toward Bizen, to the Imperial-rank carvers of Osaka who reproduced the old wave-grain while mastering the wider traditions. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Naonori直則 | 1830-1844 | 0 |
| Toshiyasu俊安 | 1504-1521 | 0 |
| Nagahisa長久 | 1334-1338 | 0 |
| Kiyoyasu清安 | 1532-1555 | 0 |
| Tomosada友定 | 1532-1555 | 0 |
Muromachi turned sword making into an industry: the uchigatana rose with massed infantry warfare, Osafune and Seki produced bundle swords beside custom orders, and the Ming trade carried Japanese blades abroad by the tens of thousands.
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 siteCustomer-initiated returns accepted within two days of arrival; return shipping paid by customer and fees non-refundable. Returns/refunds unavailable for overseas deliveries.
This is a Koto period tanto by Gassan, a rare signed example from the Muromachi period. It features a fine suguha hamon and the distinctive ayasugi-hada, a specialty of the Gassan school. The tanto comes with a luxurious aikuchi koshirae, decorated with black lacquer, vermilion cloud motifs, and silver fittings depicting waves.




Wakimono · Dewa · around 1394-1428
Tōken Taikan top 60%
2 pieces on the market now
Where Gassan 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.
Wakimono · Dewa
52 pieces on the market now
Mount Gassan rises among the Dewa Sanzan, the three sacred peaks of northern Japan bound to the mountain asceticism of Shugendō, and the swordsmiths who took the mountain's name worked in its shadow in Ōshū, Dewa Province. The setsumei record that smiths signing "Gassan" are noted in the Kanchiin-bon Meizukushi as early as the Heian period, and the lineage's oldest surviving signed blade is a tachi simply signed Gassan, kept at the Gassan Shrine and judged to date from the late Nanbokuchō to early Muromachi period. Around that same early Nanbokuchō moment the corpus places Gassan Nagamitsu, whose signed tachi answers to the "Ushū Gassan group, around the Ryakuō era" recorded in the Meikan, and Shōgun, a Nanbokuchō hand sometimes identified with Gunshō, dated Genchū 3 (1386). A later branch is carried by Gassan Chikanori, working into the mid and late Muromachi (an ubu wakizashi dated Eishō 9, 1512). The line was revived in Osaka in the closing Tokugawa and Meiji years by Gassan Sadayoshi and his adopted son Gassan Sadakazu, who endured the Haitōrei edict and was appointed Teishitsu Gigei-in (Artist to the Imperial Household) in Meiji 39; his own adopted son Gassan Sadaichi continued the title into Taishō. The forging is the school's signature. " Over the itame base the grain flows (nagare) and tends to stand; ji-nie adheres and chikei enter, and the northern steel takes a dark, metal-like (kana-iro) hue read as Ōshū temperament.
The temper of the old line is a suguha whose nioiguchi is shizumi (subdued), at times mixed with gunome and ko-midare and softened toward urumi, the bōshi turning back in ko-maru. Departures within the corpus mark the lineage's range: Chikanori's late work can drop the ayasugi entirely and absorb Sue-Bizen and Osafune manners, while the Osaka revival smiths command itame with thick ji-nie, flamboyant nie-laden midare, kinsuji, and sunagashi in a full Sōshū idiom, and both Sadakazu and Sadaichi added meticulous horimono, from Bishamonten kurikara to taki kaen Fudō and dragon carvings carved by the same hand that forged the blade. For recognition the setsumei point first to the wave-grain ayasugi and the subdued, often slightly urumi northern nioiguchi, and where these recede, to the dark steel and standing grain that still betray an Ōshū hand. Signed examples of the old line are described as extremely rare, which raises the documentary weight of Nagamitsu's tachi and Shōgun's dated tantō. Provenance threads through the school's own sanctuary: the founding tachi and an Important Art Object tachi both reside at the Dewa Sanzan and Gassan Shrines. The Osaka revival is anchored in the Imperial collection, where Sadaichi tantō signed Teishitsu Gigeiin survive, alongside a Sadakazu wakizashi made on commission for Prince Kuni. Across six centuries the setsumei track a single mountain workshop, from the subdued ayasugi of the Dewa founders through a Muromachi offshoot that turned toward Bizen, to the Imperial-rank carvers of Osaka who reproduced the old wave-grain while mastering the wider traditions. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Naonori直則 | 1830-1844 | 0 |
| Toshiyasu俊安 | 1504-1521 | 0 |
| Nagahisa長久 | 1334-1338 | 0 |
| Kiyoyasu清安 | 1532-1555 | 0 |
| Tomosada友定 | 1532-1555 | 0 |
Muromachi turned sword making into an industry: the uchigatana rose with massed infantry warfare, Osafune and Seki produced bundle swords beside custom orders, and the Ming trade carried Japanese blades abroad by the tens of thousands.
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 siteCustomer-initiated returns accepted within two days of arrival; return shipping paid by customer and fees non-refundable. Returns/refunds unavailable for overseas deliveries.