Sasanuki and the Naminohira School — Satsuma's Important Cultural Property Tachi and a Nine-Century Sword Lineage at Japan's Southern Edge

What Is Sasanuki?

Sasanuki is a tachi (long sword) attributed to Naminohira Yukiyasu, a swordsmith of Satsuma active in the Kamakura period (13th century). The blade bears the signature "Naminohira Yukiyasu" and is prized as one of the few surviving signed works of the early Yukiyasu. Handed down in Satsuma since ancient times, it has long been known by the sobriquet "Sasanuki." Today it is held by the Kyoto National Museum (Higashiyama Ward, Kyoto) and was designated an Important Cultural Property of Japan in 1972 (Showa 47).

The blade is about 72.5 cm long with a curvature of roughly 2.3 cm. It is deeply curved overall, and the tip takes the short, stout form known as ikubi-kissaki ("boar's-neck point"). The jigane (forged steel surface) shows itame grain mixed with masame, with a fine covering of ji-nie. The hamon (temper pattern) is a calm suguha (straight temper) — clear evidence that the Naminohira school, to which Yukiyasu belonged, descends from the Yamato tradition (Yamato-den). Though a koto blade forged at the far southern edge of Japan, Sasanuki is steeped in the classical aesthetic of Yamato.

Form and Workmanship — Ikubi-kissaki and Suguha

Sasanuki has a broad, dignified construction to which a deep curvature is added. The short, compressed ikubi-kissaki is a form seen on the robust tachi of the Kamakura period and is often associated with practical war blades. It is a sword that inspires reliability before elegance.

The jigane shows itame flowing into masame, with a thick, fine covering of ji-nie. The color of the steel is somewhat dark, displaying the subdued, austere texture characteristic of Satsuma work forged from the iron sand of southern Kyushu. The hamon is a suguha with a tight nioiguchi, with small irregularities and activity here and there. Without flamboyance, both ji and ha are sound and of high quality. In contrast to the bright choji-midare of the Bizen tradition or the vigorous nie-laden hamon of the Soshu tradition, this is serene, upright workmanship — the true merit of the Naminohira school as a Yamato-derived Satsuma tradition. Sasanuki attests that a provincial school could maintain a dignity rivaling the great central lineages.

The Origin of the Name "Sasanuki"

The sobriquet "Sasanuki" is bound up with a legend about the smith, Naminohira Yukiyasu. Setting out to forge a supreme blade, Yukiyasu strictly forbade his wife to look into the smithy. When she broke the prohibition and peered inside, Yukiyasu — believing his concentration ruined and the blade a failure — cast the sword away into a bamboo thicket. Thereafter, a strange light was said to shine from the thicket night after night. When people pulled the sword out to investigate, its tip was found to have pierced through countless fallen leaves of bamboo grass (sasa) that had drifted down upon it. From this tale of a blade that had pierced the sasa leaves, the name "Sasanuki" (sasa-piercing) is said to derive.

The paradoxical image — a sharpness able to pierce thin, soft bamboo-grass leaves without merely bending them — symbolizes both the cutting power of this tachi and the numinous power (reii) attributed to it. Some accounts simply explain the name as meaning the blade was sharp enough to pierce sasa, but every version turns on the single point of "piercing the sasa." That the story dwells not on a feat of cutting down men but on the mysterious power residing in the sword itself reveals the reverence the people of Satsuma felt for a supreme masterpiece.

Survival and Provenance — From the Kabayama Family to the Kyoto National Museum

Sasanuki is known as a tachi handed down in the Kabayama family, senior retainers of the Shimazu clan of Satsuma. According to tradition, the blade was once presented to the main Shimazu house, but strange occurrences persisted in the household, and it was returned to the Kabayama. Thereafter Sasanuki was carefully preserved as a Kabayama family treasure and has survived to the present together with a black-lacquered tachi mounting (kuro-urushi tachi koshirae) made in the early Muromachi period. The fittings are said to bear the Shimazu family crest of a cross within a circle.

In the modern era, Sasanuki was designated a national Important Cultural Property in 1972 (Showa 47). It is now held and preserved by the Kyoto National Museum, under the ownership of the Independent Administrative Institution National Institutes for Cultural Heritage. A blade born in Satsuma and guarded by Satsuma's warrior families is now exhibited and studied in a Kyoto national museum as a page in the history of the Japanese sword. That a tachi produced by a provincial school far from the central Five Traditions is honored as a national cultural property speaks eloquently of the high quality of Naminohira workmanship.

The Naminohira School and Naminohira Yukiyasu — From Yamato to Satsuma

The Naminohira school, which produced Sasanuki, was a school of swordsmiths based in Satsuma Province (present-day Kagoshima Prefecture), and it occupies a strikingly unusual place in the history of the Japanese sword. This is because it long preserved its own tradition in southern Kyushu, far removed from the principal sword-producing centers — Yamashiro (Kyoto), Yamato, Bizen, Sagami, and Mino, the heartlands of the so-called Five Traditions (Gokaden).

The founding ancestor of the Naminohira school is said to be Masakuni, who is held to have migrated from Yamato Province (present-day Nara) to Satsuma. However, no signed works by Masakuni are known to survive, and in practice his son, said to be Yukiyasu, is treated as the de facto founder of the school. The migration is traditionally placed in the late Heian period (around the 10th–11th centuries), though the precise date is uncertain. The school settled at Naminohira in Satsuma — the area around Higashi-taniyama in the southern part of present-day Kagoshima City — and took this place name as the name of the school.

The name "Naminohira Yukiyasu" was thereafter passed down through the main line generation after generation. From the late Heian period to the early Meiji era, the school sustained Satsuma's sword culture for roughly nine hundred years. No other lineage in the history of the Japanese sword endured for so long, and the Naminohira school is often described as the longest-lived family of swordsmiths in Japan. Yukiyasu, the maker of Sasanuki, stands among the early smiths of this long lineage, and Sasanuki is the representative work that conveys to us today the skill of the first-generation smiths of the Ko-Naminohira ("old Naminohira").

The School's Workmanship — Yamato Tradition Rooted in Satsuma

Although the Naminohira school is not counted among the Five Traditions, its workmanship clearly descends from the Yamato tradition. Consistent with the tradition that its founder came from Yamato, its blades share much with Yamato work: a quiet hamon centered on suguha, a jigane in which masame flows, and a classical tachi form with a deep curvature at the base. Sasanuki's suguha and its jigane of itame mixed with masame lie squarely within this lineage.

At the same time, the climate of southern Kyushu and the iron sand found there gave the Naminohira school its own distinctive character. The jigane tends somewhat dark, showing a whitish (shirake) tendency, and the way the nie forms has the dry quality peculiar to Satsuma work. Avoiding ostentation and prizing sturdy simplicity, this style was later often described as "Satsuma ruggedness" and spoken of alongside the temperament of the Satsuma warrior. Being a frontier region cut off from central fashions paradoxically allowed the school to preserve its archaic style in high purity. The grand, powerful Satsuma shinshinto blades that captivated so many at the end of the Edo period trace their distant source to the koto tradition the Naminohira school had cultivated ever since the Heian era.

Sasanuki as a Satsuma Blade — Appraisal, Acquisition, and Market

Naminohira blades are indispensable to any discussion of "Satsuma swords." Many people picture the bold shinshinto used in the swordfights of the late Edo period, but the wellspring of Satsuma swords lies in the koto tradition the Naminohira school had cultivated since the late Heian period. Signed works by the Ko-Naminohira, such as Sasanuki, survive in extremely small numbers; they rarely appear on the market, and when they do, they are highly valued as important reference material.

By contrast, works by later smiths who took the name "Naminohira Yukiyasu" from the Edo period onward survive in relatively greater numbers and circulate as Satsuma blades that collectors can actually acquire. Even with the same "Yukiyasu" signature, the first-generation (Ko-Naminohira) and later generations differ greatly in period, workmanship, and valuation. When acquiring one, it is therefore essential to confirm the date of manufacture (which generation of Yukiyasu) and the attribution (kiwame). Certificates from bodies such as the NBTHK (Society for the Preservation of Japanese Art Swords) help one judge the period, quality, and authenticity of the signature. Naminohira blades enjoy steady popularity among those who prefer sound, honest ji and ha over flamboyance, and they offer the distinctive appeal of savoring the classical beauty of the Yamato tradition within the setting of Satsuma.

At Toukenza, we handle the work of smiths from across Japan — including Satsuma's Naminohira school — only after confirming period, signature, condition, and the presence of appraisal papers. We hope that, through an Important Cultural Property masterpiece such as Sasanuki, you will come to know the craft of the Ko-Naminohira and explore the profound world of Satsuma swords to which it leads.