This is a Tachi by Sanenaga, said to be the son of Mitsutada and younger brother of Nagamitsu. It features a beautiful jigane with midare-utsuri and a suguha-style hamon mixed with small chouji, ashi, and you, frequently showing kinsuji. The blade has a standard mihaba, slightly deep sori, and a small, elegantly shaped kissaki, making it a masterpiece.
NihontoWatchmei · Shoan (1299-1302) · nagasa 71.2cm · sori 1.8cm
Osafune (Bizen) · Bizen · around 1299-1309
Fujishiro Sai-jo saku · Tōken Taikan top 5%
2 pieces on the market now
Sanenaga is the quiet member of the Osafune mainline, recorded in the Kokon Mei Zukushi as a son of Mitsutada and the younger brother of Nagamitsu, and active in the late Kamakura period. Where his father and brother are read by their flamboyant choji, Sanenaga is the smith in whom the school's calm straight temper finds its surest hand, and it is in suguha that his work is most confidently identified. The published sources return to the same description again and again: within the Osafune group of his time he excelled at a gentle suguha-toned temper, and a hallmark of his work is the well-tightened nioiguchi.
The signature that survives is itself part of the study of him. Blades carry both a two-character signature and a longer one, and among the long signatures are dated works inscribed Shoan, Kagen, Tokuji and Engyo. The Kokon Mei Zukushi places the first Sanenaga in the Bun'ei and Koan years and treats the dated long signatures of Shoan and after as a second generation, though the question of one against two generations is still left open in the published record. The undated two-character pieces are read as the earlier hand, the dated long signatures as the later, and this division gives the connoisseur a rare double anchor of style and date.
The jigane is the refined ko-itame of the direct line, tightly forged and often mixed with mokume and itame, with ji-nie lying microscopically fine and delicate chikei entering the steel. Over it a midare-utsuri stands up vividly, and on some blades a more linear, suji-like utsuri runs toward the edge before breaking into the midare form higher up. This is the bright, well-knit jigane the appraisers expect of the Osafune mainline, and it is the floor on which Sanenaga's tempering is read.
The hamon is built on a chu-suguha mixed with ko-choji, ko-gunome and a little ko-notare, into which ko-ashi and yo enter; the nioiguchi tends to tighten and carries slight ko-nie, with fine sunagashi at times, and it comes up bright and clear. The boshi is the calm point that completes the picture: it goes in with a shallow notare and turns back small in ko-maru[[c:1]], the composed turnback that suits the tightened straight temper below it. It is this quiet, controlled finish, jigane, hamon and boshi all of a piece, that the published sources call his typical manner.
A second and rarer manner exists. On a small number of blades the temper opens into a comparatively flamboyant midare of choji and gunome, somewhat saka-gakari, close enough that it can be mistaken for his brother Nagamitsu[[c:2]]. The tell that keeps the two apart is the nioiguchi, which on Sanenaga stays tighter and cooler in every case; the appraisers note that whichever manner appears, the nioiguchi remains characteristically tight. A few kodachi also survive under his name, an uncommon survival shared in the school chiefly with Mitsutada and Nagamitsu.
For the collector, Sanenaga is Sai-jo saku in Fujishiro's grading, and the record of him is largely a record of the great houses. A signed tachi was transmitted in the Satsuma Shimazu family, carrying a Hon'ami Kotsune origami noted in the family's 1928 sale catalog; another came down through the Kaga Maeda family with a Hon'ami appraisal, and a signed tachi with its koshirae passed through the Odawara Okubo house. Ten of his blades stand in the Tokuju tier and forty-two more in Juyo, and his work is held in the Imperial collection and through the Date, Shimazu, Maeda and Hosokawa houses. Within his own family he is the counterweight to his brother: where Nagamitsu is plump and flamboyant, Sanenaga is the disciplined hand that shows how refined a plain Bizen suguha can be made, and a blade in his calm manner is among the harder Osafune names to bring to hand.
Where Sanenaga 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
Bizen-den · Bizen
Phase: Ko-Osafune古長船· 1238–1335
235 pieces on the market now
Three smiths working at the village of Osafune across the second half of the thirteenth century set the terms for every Bizen blade that followed: Mitsutada the founder, his son Nagamitsu, and the closely related Sanenaga, the Sansaku triumvirate whose work opens this phase. Their window runs from the mid-Kamakura period into the early fourteenth century, when leadership passed to Nagamitsu's son Kagemitsu, the third-generation head whose dated tachi, naginata, and tanto carry the phase to its close around the Kenmu years. The setsumei repeatedly fix Kagemitsu by genealogy and date, citing pieces inscribed from Gen'o 1 (1319) and Genko 1 (1321) through Shochu and Kenmu (1325 to 1334); these ubu or lightly shortened, date-bearing blades are what give the founding chapter its firm chronological spine and separate it from the workshop-broad output of the later Nanbokucho and Oei generations. This is the orthodox mainline before the school fanned out: the generation that built the standard, not the ones that later reinterpreted it. The constructional signature of the phase is a tightly packed ko-itame, at times mixed with mokume, carrying fine ji-nie in dense particles, fine chikei, and a vivid midare-utsuri that the examiners single out again and again; one Kagemitsu tachi even pushes the utsuri toward a striped, Aoe-like dan-utsuri with reverse-slanting dark bands. Against the Ko-Bizen root, with its standing jifu-utsuri and thicker ha-nie, this phase reads as more refined and more tightly controlled in the ji. The temper marks the phase's internal turn.
Where Nagamitsu and Mitsutada favored flamboyant choji-midare, Kagemitsu pulls the hand inward to a suguha-based temper carrying ko-gunome, ko-choji, and angular elements, often with a reverse (saka-gakari) tendency, in a nioi-dominant, bright nioiguchi; the setsumei credit him specifically with perfecting kata-ochi gunome, the dropped-shoulder pattern repeatedly named as his completion. The boshi is the gentle sansaku-boshi, a shallow midare-komi or notare turning back in ko-maru. None of this is the powerful nie, scattered tobiyaki, and Soshu-den drama of the later Soden-Bizen, nor the open gunome and pointed candlewick boshi of the Oei revival; it is calmer, nioi-bound, and date-anchored. A collector separates this phase by its named masters and the kantei points the setsumei make explicit: kata-ochi gunome and the sansaku-boshi read Kagemitsu, while reverse-slanting jihan-utsuri and certain boshi forms let the examiners assign proxy daimei hands such as Chikakage and the collaborator Kagemasa, the latter named in a Shochu 2 (1325) joint tachi dedicated to Chichibu Shrine. Tanto are a discriminator in their own right, surviving in number for Kagemitsu where they are scarce for Nagamitsu, including the kanmuri-otoshi and hira-zukuri pieces with devotional bonji and kurikara carvings. Provenance present in the sample carries weight: a Kagemitsu tachi transmitted in the Chikuzen Kuroda family with its old scabbard, an orikaeshi-mei katana recorded in the Shimazu line, and tanto and tachi held in the Imperial collection where Kagemitsu is ranked beside Yoshimitsu, Shintogo Kunishige, and Samonji. These are the works that define the founding core against everything Osafune later became. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Mitsutada光忠 | 1238-1239 | 60 |
| Nagamitsu長光 | 1274-1304 | 244 |
| Kagemitsu景光 | 1303-1336 | 143 |
| Kanemitsu兼光 | 1323-1370 | 231 |
| Sanenaga眞長 | 1299-1309 | 64 |
Bizen in the Kamakura period
Kamakura was Bizen’s summit. Tradition places Ichimonji smiths among Go-Toba’s goban kaji, Mitsutada founded the Osafune line at mid-century, and orders flowed from the court and the warrior government alike. No province holds more National Treasure blades.
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/cancellations not accepted after shipment except for significant defects; if defective, return/exchange possible within 3 days of arrival (return shipping paid by customer).
¥7,500,000
This is a Tachi by Sanenaga, said to be the son of Mitsutada and younger brother of Nagamitsu. It features a beautiful jigane with midare-utsuri and a suguha-style hamon mixed with small chouji, ashi, and you, frequently showing kinsuji. The blade has a standard mihaba, slightly deep sori, and a small, elegantly shaped kissaki, making it a masterpiece.
NihontoWatchmei · Shoan (1299-1302) · nagasa 71.2cm · sori 1.8cm
Osafune (Bizen) · Bizen · around 1299-1309
Fujishiro Sai-jo saku · Tōken Taikan top 5%
2 pieces on the market now
Sanenaga is the quiet member of the Osafune mainline, recorded in the Kokon Mei Zukushi as a son of Mitsutada and the younger brother of Nagamitsu, and active in the late Kamakura period. Where his father and brother are read by their flamboyant choji, Sanenaga is the smith in whom the school's calm straight temper finds its surest hand, and it is in suguha that his work is most confidently identified. The published sources return to the same description again and again: within the Osafune group of his time he excelled at a gentle suguha-toned temper, and a hallmark of his work is the well-tightened nioiguchi.
The signature that survives is itself part of the study of him. Blades carry both a two-character signature and a longer one, and among the long signatures are dated works inscribed Shoan, Kagen, Tokuji and Engyo. The Kokon Mei Zukushi places the first Sanenaga in the Bun'ei and Koan years and treats the dated long signatures of Shoan and after as a second generation, though the question of one against two generations is still left open in the published record. The undated two-character pieces are read as the earlier hand, the dated long signatures as the later, and this division gives the connoisseur a rare double anchor of style and date.
The jigane is the refined ko-itame of the direct line, tightly forged and often mixed with mokume and itame, with ji-nie lying microscopically fine and delicate chikei entering the steel. Over it a midare-utsuri stands up vividly, and on some blades a more linear, suji-like utsuri runs toward the edge before breaking into the midare form higher up. This is the bright, well-knit jigane the appraisers expect of the Osafune mainline, and it is the floor on which Sanenaga's tempering is read.
The hamon is built on a chu-suguha mixed with ko-choji, ko-gunome and a little ko-notare, into which ko-ashi and yo enter; the nioiguchi tends to tighten and carries slight ko-nie, with fine sunagashi at times, and it comes up bright and clear. The boshi is the calm point that completes the picture: it goes in with a shallow notare and turns back small in ko-maru[[c:1]], the composed turnback that suits the tightened straight temper below it. It is this quiet, controlled finish, jigane, hamon and boshi all of a piece, that the published sources call his typical manner.
A second and rarer manner exists. On a small number of blades the temper opens into a comparatively flamboyant midare of choji and gunome, somewhat saka-gakari, close enough that it can be mistaken for his brother Nagamitsu[[c:2]]. The tell that keeps the two apart is the nioiguchi, which on Sanenaga stays tighter and cooler in every case; the appraisers note that whichever manner appears, the nioiguchi remains characteristically tight. A few kodachi also survive under his name, an uncommon survival shared in the school chiefly with Mitsutada and Nagamitsu.
For the collector, Sanenaga is Sai-jo saku in Fujishiro's grading, and the record of him is largely a record of the great houses. A signed tachi was transmitted in the Satsuma Shimazu family, carrying a Hon'ami Kotsune origami noted in the family's 1928 sale catalog; another came down through the Kaga Maeda family with a Hon'ami appraisal, and a signed tachi with its koshirae passed through the Odawara Okubo house. Ten of his blades stand in the Tokuju tier and forty-two more in Juyo, and his work is held in the Imperial collection and through the Date, Shimazu, Maeda and Hosokawa houses. Within his own family he is the counterweight to his brother: where Nagamitsu is plump and flamboyant, Sanenaga is the disciplined hand that shows how refined a plain Bizen suguha can be made, and a blade in his calm manner is among the harder Osafune names to bring to hand.
Where Sanenaga 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
Bizen-den · Bizen
Phase: Ko-Osafune古長船· 1238–1335
235 pieces on the market now
Three smiths working at the village of Osafune across the second half of the thirteenth century set the terms for every Bizen blade that followed: Mitsutada the founder, his son Nagamitsu, and the closely related Sanenaga, the Sansaku triumvirate whose work opens this phase. Their window runs from the mid-Kamakura period into the early fourteenth century, when leadership passed to Nagamitsu's son Kagemitsu, the third-generation head whose dated tachi, naginata, and tanto carry the phase to its close around the Kenmu years. The setsumei repeatedly fix Kagemitsu by genealogy and date, citing pieces inscribed from Gen'o 1 (1319) and Genko 1 (1321) through Shochu and Kenmu (1325 to 1334); these ubu or lightly shortened, date-bearing blades are what give the founding chapter its firm chronological spine and separate it from the workshop-broad output of the later Nanbokucho and Oei generations. This is the orthodox mainline before the school fanned out: the generation that built the standard, not the ones that later reinterpreted it. The constructional signature of the phase is a tightly packed ko-itame, at times mixed with mokume, carrying fine ji-nie in dense particles, fine chikei, and a vivid midare-utsuri that the examiners single out again and again; one Kagemitsu tachi even pushes the utsuri toward a striped, Aoe-like dan-utsuri with reverse-slanting dark bands. Against the Ko-Bizen root, with its standing jifu-utsuri and thicker ha-nie, this phase reads as more refined and more tightly controlled in the ji. The temper marks the phase's internal turn.
Where Nagamitsu and Mitsutada favored flamboyant choji-midare, Kagemitsu pulls the hand inward to a suguha-based temper carrying ko-gunome, ko-choji, and angular elements, often with a reverse (saka-gakari) tendency, in a nioi-dominant, bright nioiguchi; the setsumei credit him specifically with perfecting kata-ochi gunome, the dropped-shoulder pattern repeatedly named as his completion. The boshi is the gentle sansaku-boshi, a shallow midare-komi or notare turning back in ko-maru. None of this is the powerful nie, scattered tobiyaki, and Soshu-den drama of the later Soden-Bizen, nor the open gunome and pointed candlewick boshi of the Oei revival; it is calmer, nioi-bound, and date-anchored. A collector separates this phase by its named masters and the kantei points the setsumei make explicit: kata-ochi gunome and the sansaku-boshi read Kagemitsu, while reverse-slanting jihan-utsuri and certain boshi forms let the examiners assign proxy daimei hands such as Chikakage and the collaborator Kagemasa, the latter named in a Shochu 2 (1325) joint tachi dedicated to Chichibu Shrine. Tanto are a discriminator in their own right, surviving in number for Kagemitsu where they are scarce for Nagamitsu, including the kanmuri-otoshi and hira-zukuri pieces with devotional bonji and kurikara carvings. Provenance present in the sample carries weight: a Kagemitsu tachi transmitted in the Chikuzen Kuroda family with its old scabbard, an orikaeshi-mei katana recorded in the Shimazu line, and tanto and tachi held in the Imperial collection where Kagemitsu is ranked beside Yoshimitsu, Shintogo Kunishige, and Samonji. These are the works that define the founding core against everything Osafune later became. Learn more →
| Smith | Era | Designated |
|---|---|---|
| Mitsutada光忠 | 1238-1239 | 60 |
| Nagamitsu長光 | 1274-1304 | 244 |
| Kagemitsu景光 | 1303-1336 | 143 |
| Kanemitsu兼光 | 1323-1370 | 231 |
| Sanenaga眞長 | 1299-1309 | 64 |
Bizen in the Kamakura period
Kamakura was Bizen’s summit. Tradition places Ichimonji smiths among Go-Toba’s goban kaji, Mitsutada founded the Osafune line at mid-century, and orders flowed from the court and the warrior government alike. No province holds more National Treasure blades.
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/cancellations not accepted after shipment except for significant defects; if defective, return/exchange possible within 3 days of arrival (return shipping paid by customer).
¥7,500,000
