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Description

This is an unsigned Katana attributed to Ko Mihara, designated as an 18th session Juyo Token by the NBTHK. It features a nagasa of 75.0 cm, a well-forged jitetsu with itame and mokume, and a suguha-based hamon with slight notare. The blade is described as healthy and elegant, showcasing characteristics of both Yamato and Aoe traditions.

NBTHK Setsumei

Jūyō-Tōken, 18th Session — Designated April 24, 1969 Katana, mumei: Ko-Mihara (古三原) Measurements Nagasa approx. 75.0 cm, sori 1.8 cm, motohaba 2.9 cm, sakihaba 2.1 cm, kissaki-nagasa 3.5 cm, nakago-nagasa 20.6 cm, nakago-sori slight Description Keijō: shinogi-zukuri, iori-mune, ō-suriage (greatly shortened), with slightly shallow sori and a chū-kissaki. Kitae: itame-hada mixed with ō-itame; toward the cutting edge it tends to masame; the hada stands out somewhat, and ji-nie adheres. Hamon: chū-suguha; in places small ashi enter; the nioiguchi tends toward being tight, with small nie adhering. Bōshi: Straight, turning back in ko-maru; on the reverse there is slight hakikake. Horimono: On both sides a bō-hi is carved and run off (kaki-nagashi). Nakago: ō-suriage; kiri-jiri; yasurime are katte-sagari; four mekugi-ana (the two central holes are plugged); unsigned. Artisan Ko-Mihara school Era Late Kamakura to Nanbokuchō period Explanation This is an unsigned katana that has been greatly shortened (ō-suriage), and it has been appraised as work of Ko-Mihara. The term “Ko-Mihara” is used as a general designation for works of the Mihara group dating to the late Kamakura period and the Nanbokuchō period. The Mihara school was a lineage that resided at Mihara in Bingo Province. It began in the late Kamakura period and continued to prosper through to the end of the Muromachi period. Across the various eras, Mihara works show strong influence from Yamato swords. The school specialized in suguha, and its output tends to exhibit relatively little overt individuality. This katana is a typical work of the Ko-Mihara school, and both the jihada and the tempered edge are in kenzen (sound and well-preserved) condition.

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Swords›Yamato-den›Mihara›Ko-Mihara›Katana: Ko Mihara (Unsigned)
katanaJūyō
Ko-Mihara School

Katana: Ko Mihara (Unsigned)

mumei · Mihara · Koto · nagasa 75cm · sori 1.8cm

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Measurements & details
Smith
Ko-Mihara School
Type
Katana
School
Ko-Mihara
Period
Koto(Late Kamakura)
Province
Bingo
Signature
Unsigned(0% of this smith's designated works are signed)
Measurements
Nagasa 75cmSori 1.8cmMotohaba 2.99cmSakihaba 2.09cmKasane 0.67cm
Description

This is an unsigned Katana attributed to Ko Mihara, designated as an 18th session Juyo Token by the NBTHK. It features a nagasa of 75.0 cm, a well-forged jitetsu with itame and mokume, and a suguha-based hamon with slight notare. The blade is described as healthy and elegant, showcasing characteristics of both Yamato and Aoe traditions.

NBTHK Zufu Commentary

Juyo #18

AI translation — may contain errors

-, 18th Session — Designated April 24, 1969

, : Ko- (古三原)

Measurements approx. 75.0 cm, 1.8 cm, 2.9 cm, 2.1 cm, 3.5 cm, 20.6 cm, slight

Description Keijō: , , (greatly shortened), with slightly shallow and a . : mixed with ; toward the cutting edge it tends to ; the stands out somewhat, and adheres. : ; in places small enter; the tends toward being tight, with small adhering. : Straight, turning back in ; on the reverse there is slight . : On both sides a is carved and run off (kaki-nagashi). : ; ; are ; four (the two central holes are plugged); unsigned.

Artisan Ko- school

Era Late to period

Explanation This is an unsigned that has been greatly shortened (), and it has been appraised as work of Ko-.

The term “Ko-” is used as a general designation for works of the group dating to the late period and the period. The school was a lineage that resided at in Bingo Province. It began in the late period and continued to prosper through to the end of the period.

Across the various eras, works show strong influence from Yamato swords. The school specialized in , and its output tends to exhibit relatively little overt individuality.

This is a typical work of the Ko- school, and both the and the tempered edge are in (sound and well-preserved) condition.

About the school

Ko-Mihara

古三原

Yamato-den · Bingo

7 pieces on the market now

›

Bingo province, and the town of Mihara on the Numata river within it, gives this school its name. The Mihara group arose at the close of the Kamakura period and worked on through the Nanbokucho years, and the published sources gather the work of that early phase under the collective name Ko-Mihara, reserving Sue-Mihara for the late-Muromachi continuation of the line. What shaped the early smiths was geography turned to craft: Bingo held many estates (shoen) of the great Kinai temples and shrines, Toji and the Rengeo-in among them, and the exchange that came with those holdings carried the manner of Yamato into Bingo steel. The two names that stand at the head of the group are Masaie, traditionally made the founder and head of the school, and Masahiro, transmitted as his son or pupil; the record qualifies that tradition from the blades themselves, for signed Masahiro reads the more archaic of the two and neither name belongs to a single hand, the NBTHK gathering several generations under each attribution. Around them work Masanobu and Masamune, named as the smiths who adorned the finale of the line, while the neighboring Kokubunji and Hokke (Ashida) groups, the Sukekuni and Kaneyasu lineages, stand within the same Yamato-influenced Bingo orbit and are forever compared against Mihara in the very texts that designate their blades. The school speaks in one quiet vocabulary across its members. Over an itame mixed with mokume and flowing nagare-hada that stands rather than lies flat and tends to masame along the edge, the smiths lay fine ji-nie, with chikei entering and patches of jifu; a pale shirake-utsuri rises in the ground of more than half the surviving blades, the steel often reading dark beneath it. The temper is a refined suguha or chu-suguha, narrow and restrained, mixing ko-gunome and a slight ko-midare tendency, with ko-ashi and yo entering well; the habuchi frays into hotsure and kuichigai-ba, kinsuji and sunagashi thread the ha, and the nioiguchi stays tight with ko-nie rather than glowing with heavy nie. The boshi runs straight to a gentle ko-maru, often brushed with hakikake, and burns yakizume only on the rarest piece, a calmer return than the Yamato schools proper. The published formula separates the group from those schools in a recurring phrase: compared with Yamato proper the nie of ji and ha runs weaker, the moku stands out, the shirake-utsuri is conspicuous, and the boshi turns back in a rounded manner.

Within this one discipline the hands divide. Masaie carries bold o-kissaki and the superior ground that lets a kiwame settle on him; Masahiro shows a moderate kissaki and more midare feeling and activity within the ha. The same divergence runs forward to the Sue-Mihara of late Muromachi, whose work loosens from the refined early manner. For kantei, the Ko-Mihara hand is read by the ji and the ha, not by drama of temper: the standing whitish itame tending masame, the quiet suguha with its hotsure and kuichigai-ba, the rounded hakikake boshi. Against the Yamato Nara schools the tell is the weaker nie, the tighter nioiguchi and the rounded rather than yakizume return; against the later Sue-Mihara it is the refinement and discipline the early smiths keep. A persistent confusion is Bitchu Aoe, the Shinkan Hidensho writing of old that Mihara's face resembles a Bitchu tachi; the midare-utsuri and deep-burning Mihara-boshi of certain pieces invite the comparison, which the high shinogi, the shirake-utsuri and the futae-ha hold back toward Mihara. Sukekuni adds a jifu-like utsuri recalling Bizen Unrui that marks him within the group; Kaneyasu keeps the Hokke line apart by its elevated shinogi. The best members stand high in the Yamato-den register, Masaie and Masahiro at its head, the meibutsu O-Mihara, a kinzogan-mei katana, invoked for the strikingly deep turnback of the school. Because Yamato discipline kept the early smiths sparing of signature, much of the corpus is o-suriage mumei katana settled onto these names by later connoisseurs, several by gold-inlay attribution; the surviving signed and dated tachi, scarce and prized as historical material, carry the chronology of the line. Recorded provenance runs to the first holders, the Tokugawa, the Date, the Shimazu and the Maeda houses and the Imperial collection among them, the finest pieces held in museum and patrimony rather than traded. Learn more →

9 recorded smiths206 designated works
Leading smiths
SmithEraDesignated
Masahiro正廣1362-138933
Masaie正家1353-137529
Kaneyasu兼安1352-136912
Masanobu正信1376-13944
Masamune政宗1381-13840
Explore the Ko-Mihara school →

Historical context

Yamato in the Nanbokuchō period

›

When the Southern Court made its capital at Yoshino, in Yamato itself, the province’s schools were at their height: the late Tegai line, Shikkake Norinaga, and the pure masame of Hōshō. Their technique was already spreading across the provinces.

Yamato in the Nanbokuchō period →

NBTHK Certificate
Jūyō Tōken重要刀剣
Important Sword
›

A blade of top-grade workmanship and condition, formally judged to rank with a nationally recognized Important Art Object (Jūyō Bijutsuhin). Awarded only at the NBTHK’s competitive annual examination.

Of Japan’s roughly 2.5 million registered swords, only 12,307 (about 1 in 203) have ever attained Jūyō.

About the NBTHK›

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 site→
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Description

This is an unsigned Katana attributed to Ko Mihara, designated as an 18th session Juyo Token by the NBTHK. It features a nagasa of 75.0 cm, a well-forged jitetsu with itame and mokume, and a suguha-based hamon with slight notare. The blade is described as healthy and elegant, showcasing characteristics of both Yamato and Aoe traditions.

NBTHK Setsumei

Jūyō-Tōken, 18th Session — Designated April 24, 1969 Katana, mumei: Ko-Mihara (古三原) Measurements Nagasa approx. 75.0 cm, sori 1.8 cm, motohaba 2.9 cm, sakihaba 2.1 cm, kissaki-nagasa 3.5 cm, nakago-nagasa 20.6 cm, nakago-sori slight Description Keijō: shinogi-zukuri, iori-mune, ō-suriage (greatly shortened), with slightly shallow sori and a chū-kissaki. Kitae: itame-hada mixed with ō-itame; toward the cutting edge it tends to masame; the hada stands out somewhat, and ji-nie adheres. Hamon: chū-suguha; in places small ashi enter; the nioiguchi tends toward being tight, with small nie adhering. Bōshi: Straight, turning back in ko-maru; on the reverse there is slight hakikake. Horimono: On both sides a bō-hi is carved and run off (kaki-nagashi). Nakago: ō-suriage; kiri-jiri; yasurime are katte-sagari; four mekugi-ana (the two central holes are plugged); unsigned. Artisan Ko-Mihara school Era Late Kamakura to Nanbokuchō period Explanation This is an unsigned katana that has been greatly shortened (ō-suriage), and it has been appraised as work of Ko-Mihara. The term “Ko-Mihara” is used as a general designation for works of the Mihara group dating to the late Kamakura period and the Nanbokuchō period. The Mihara school was a lineage that resided at Mihara in Bingo Province. It began in the late Kamakura period and continued to prosper through to the end of the Muromachi period. Across the various eras, Mihara works show strong influence from Yamato swords. The school specialized in suguha, and its output tends to exhibit relatively little overt individuality. This katana is a typical work of the Ko-Mihara school, and both the jihada and the tempered edge are in kenzen (sound and well-preserved) condition.

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Swords›Yamato-den›Mihara›Ko-Mihara›Katana: Ko Mihara (Unsigned)
katanaJūyō
Ko-Mihara School

Katana: Ko Mihara (Unsigned)

mumei · Mihara · Koto · nagasa 75cm · sori 1.8cm

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KatanaJūyō
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Ko-Mihara School — 1 of 7
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KatanaJūyō
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Measurements & details
Smith
Ko-Mihara School
Type
Katana
School
Ko-Mihara
Period
Koto(Late Kamakura)
Province
Bingo
Signature
Unsigned(0% of this smith's designated works are signed)
Measurements
Nagasa 75cmSori 1.8cmMotohaba 2.99cmSakihaba 2.09cmKasane 0.67cm
Description

This is an unsigned Katana attributed to Ko Mihara, designated as an 18th session Juyo Token by the NBTHK. It features a nagasa of 75.0 cm, a well-forged jitetsu with itame and mokume, and a suguha-based hamon with slight notare. The blade is described as healthy and elegant, showcasing characteristics of both Yamato and Aoe traditions.

NBTHK Zufu Commentary

Juyo #18

AI translation — may contain errors

-, 18th Session — Designated April 24, 1969

, : Ko- (古三原)

Measurements approx. 75.0 cm, 1.8 cm, 2.9 cm, 2.1 cm, 3.5 cm, 20.6 cm, slight

Description Keijō: , , (greatly shortened), with slightly shallow and a . : mixed with ; toward the cutting edge it tends to ; the stands out somewhat, and adheres. : ; in places small enter; the tends toward being tight, with small adhering. : Straight, turning back in ; on the reverse there is slight . : On both sides a is carved and run off (kaki-nagashi). : ; ; are ; four (the two central holes are plugged); unsigned.

Artisan Ko- school

Era Late to period

Explanation This is an unsigned that has been greatly shortened (), and it has been appraised as work of Ko-.

The term “Ko-” is used as a general designation for works of the group dating to the late period and the period. The school was a lineage that resided at in Bingo Province. It began in the late period and continued to prosper through to the end of the period.

Across the various eras, works show strong influence from Yamato swords. The school specialized in , and its output tends to exhibit relatively little overt individuality.

This is a typical work of the Ko- school, and both the and the tempered edge are in (sound and well-preserved) condition.

About the school

Ko-Mihara

古三原

Yamato-den · Bingo

7 pieces on the market now

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Bingo province, and the town of Mihara on the Numata river within it, gives this school its name. The Mihara group arose at the close of the Kamakura period and worked on through the Nanbokucho years, and the published sources gather the work of that early phase under the collective name Ko-Mihara, reserving Sue-Mihara for the late-Muromachi continuation of the line. What shaped the early smiths was geography turned to craft: Bingo held many estates (shoen) of the great Kinai temples and shrines, Toji and the Rengeo-in among them, and the exchange that came with those holdings carried the manner of Yamato into Bingo steel. The two names that stand at the head of the group are Masaie, traditionally made the founder and head of the school, and Masahiro, transmitted as his son or pupil; the record qualifies that tradition from the blades themselves, for signed Masahiro reads the more archaic of the two and neither name belongs to a single hand, the NBTHK gathering several generations under each attribution. Around them work Masanobu and Masamune, named as the smiths who adorned the finale of the line, while the neighboring Kokubunji and Hokke (Ashida) groups, the Sukekuni and Kaneyasu lineages, stand within the same Yamato-influenced Bingo orbit and are forever compared against Mihara in the very texts that designate their blades. The school speaks in one quiet vocabulary across its members. Over an itame mixed with mokume and flowing nagare-hada that stands rather than lies flat and tends to masame along the edge, the smiths lay fine ji-nie, with chikei entering and patches of jifu; a pale shirake-utsuri rises in the ground of more than half the surviving blades, the steel often reading dark beneath it. The temper is a refined suguha or chu-suguha, narrow and restrained, mixing ko-gunome and a slight ko-midare tendency, with ko-ashi and yo entering well; the habuchi frays into hotsure and kuichigai-ba, kinsuji and sunagashi thread the ha, and the nioiguchi stays tight with ko-nie rather than glowing with heavy nie. The boshi runs straight to a gentle ko-maru, often brushed with hakikake, and burns yakizume only on the rarest piece, a calmer return than the Yamato schools proper. The published formula separates the group from those schools in a recurring phrase: compared with Yamato proper the nie of ji and ha runs weaker, the moku stands out, the shirake-utsuri is conspicuous, and the boshi turns back in a rounded manner.

Within this one discipline the hands divide. Masaie carries bold o-kissaki and the superior ground that lets a kiwame settle on him; Masahiro shows a moderate kissaki and more midare feeling and activity within the ha. The same divergence runs forward to the Sue-Mihara of late Muromachi, whose work loosens from the refined early manner. For kantei, the Ko-Mihara hand is read by the ji and the ha, not by drama of temper: the standing whitish itame tending masame, the quiet suguha with its hotsure and kuichigai-ba, the rounded hakikake boshi. Against the Yamato Nara schools the tell is the weaker nie, the tighter nioiguchi and the rounded rather than yakizume return; against the later Sue-Mihara it is the refinement and discipline the early smiths keep. A persistent confusion is Bitchu Aoe, the Shinkan Hidensho writing of old that Mihara's face resembles a Bitchu tachi; the midare-utsuri and deep-burning Mihara-boshi of certain pieces invite the comparison, which the high shinogi, the shirake-utsuri and the futae-ha hold back toward Mihara. Sukekuni adds a jifu-like utsuri recalling Bizen Unrui that marks him within the group; Kaneyasu keeps the Hokke line apart by its elevated shinogi. The best members stand high in the Yamato-den register, Masaie and Masahiro at its head, the meibutsu O-Mihara, a kinzogan-mei katana, invoked for the strikingly deep turnback of the school. Because Yamato discipline kept the early smiths sparing of signature, much of the corpus is o-suriage mumei katana settled onto these names by later connoisseurs, several by gold-inlay attribution; the surviving signed and dated tachi, scarce and prized as historical material, carry the chronology of the line. Recorded provenance runs to the first holders, the Tokugawa, the Date, the Shimazu and the Maeda houses and the Imperial collection among them, the finest pieces held in museum and patrimony rather than traded. Learn more →

9 recorded smiths206 designated works
Leading smiths
SmithEraDesignated
Masahiro正廣1362-138933
Masaie正家1353-137529
Kaneyasu兼安1352-136912
Masanobu正信1376-13944
Masamune政宗1381-13840
Explore the Ko-Mihara school →

Historical context

Yamato in the Nanbokuchō period

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When the Southern Court made its capital at Yoshino, in Yamato itself, the province’s schools were at their height: the late Tegai line, Shikkake Norinaga, and the pure masame of Hōshō. Their technique was already spreading across the provinces.

Yamato in the Nanbokuchō period →

NBTHK Certificate
Jūyō Tōken重要刀剣
Important Sword
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A blade of top-grade workmanship and condition, formally judged to rank with a nationally recognized Important Art Object (Jūyō Bijutsuhin). Awarded only at the NBTHK’s competitive annual examination.

Of Japan’s roughly 2.5 million registered swords, only 12,307 (about 1 in 203) have ever attained Jūyō.

About the NBTHK›

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 site→
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Previously sold — Ko-Mihara School

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