Large Swords (Ōdachi & Nodachi): Japan's Largest Blades Over 90cm—Complete Guide to Uses, History, and Existing Masterpieces

Large Swords (Odachi) and Field Swords (Nodachi): Definition and Scale

In the classification of Japanese swords, those with a blade length (excluding the nakago) of 2 shaku (approximately 60cm) or more are called tachi or uchi-gatana, while those of 3 shaku (approximately 90cm) or longer are customarily called "odachi" (large sword) or "nodachi" (field sword). In the largest examples, blade length reaches 4–5 shaku (120–150cm), sometimes approaching or exceeding the height of an adult male. The weight is several times that of a normal tachi (approximately 800g–1.2kg), with specimens exceeding 4–6kg being not uncommon.

Odachi and nodachi are often used interchangeably, but the original meanings carry subtle differences. Odachi refers primarily to large swords made for ritual and votive purposes, with many created as offerings to shrines. Emphasis is placed on the beauty of the blade and the splendor of the fittings. In contrast, nodachi refers to large blades used in open-field actual combat, where practicality takes priority. The method of carrying also differed significantly from normal tachi (worn at the waist), with "seoi" (back-carrying) or "mochidachi" (attendant-carried) being more common.

How was a sword with a blade exceeding one meter in length manufactured? Every step—from iron selection through repeated folding and hardening—required multiple times the effort of a normal sword. Achieving a uniform hardened edge along the entire length required meticulous temperature control and exceptional skill, and the very existence of odachi testified to the highest level of a swordsmith's capabilities.

The hardening process was the greatest challenge in odachi forging. When imprinting the hamon, clay is applied in sections and the long blade rapidly cooled—a process in which steel shrinkage tends to be uneven across different areas, and thermal stress misalignment can cause warping (sori) or cracks. Errors that an experienced craftsman could control in a normal sword meant complete loss in an odachi exceeding 3 shaku. Because of these high risks, the names of smiths who completed odachi have been recorded with special respect.

Distinguishing Odachi, Nodachi, and Tachi: "How Long Must a Sword Be to Be Called Odachi?"

Both odachi and nodachi are read as ōdachi/nodachi and refer essentially to the same large blade, distinguished in naming. When making a distinction, odachi is the term emphasizing artistic beauty for ritual and votive purposes, while nodachi stresses practical use in field combat—a difference in nuance rather than any strict formal distinction in blade shape.

The criterion distinguishing a normal tachi or uchi-gatana from an odachi lies in blade length. While swords of 2 shaku (approximately 60cm) or longer are called tachi or uchi-gatana, those of 3 shaku (approximately 90cm) or more are generally called odachi or nodachi. However, some researchers argue for 85cm and above as odachi, and no fixed numerical boundary has been formally established. The term is best understood as denoting "a blade of exceptional length, far exceeding standard tachi proportions."

The historical chronicle "Taiheiki" contains numerous references to odachi exceeding 5 shaku (approximately 150cm), including accounts of a 5-shaku 6-sun (approximately 170cm) odachi belonging to Osamu Odaka, a 7-shaku 3-sun (approximately 221cm) odachi of Saburō Fukuma, and descriptions reaching as much as 9-shaku 3-sun (approximately 282cm). While literary exaggeration must be considered, such accounts demonstrate how much martial authority warriors of the Nanboku-cho period placed in wielding exceptionally long blades.

Technical Challenges in Odachi Forging: From Tamahagane Procurement to Hardening

Manufacturing odachi differs fundamentally from normal swords beginning at the material selection stage. Since quality tamahagane obtained from a single tatara operation is limited in quantity, forging a single odachi required careful selection and combination of materials from multiple smelt cycles. When renowned smiths of Osafune or the Soshu tradition forged odachi, they consumed 2–3 times the tamahagane of a normal sword, requiring special procurement systems even at the materials stage.

In the folding and forge-welding process, spreading the extended blade uniformly required workshop space and multiple assistants. Forge cracks (kitaewere) and lamination irregularities (tsumiori) occurring during forging could be discarded in shorter blades but left no margin in odachi. A quenching tank larger than normal was necessary, and the timing of rapid cooling, water temperature, and angle of withdrawal depended entirely on the craftsman's intuition. That smiths of the Nanboku-cho period solved this challenge is an outstanding technical achievement recognized even by modern metallurgists.

The Nanboku-cho Era: The Golden Age of Odachi

Odachi were most actively forged during the Nanboku-cho period (1336–1392). Following the collapse of Emperor Go-Daigo's Restoration (Kenmu), over half a century of conflict between the Northern Court led by Ashikaga Takauji and the Emperor Go-Daigo's Southern Court saw large-scale battles across the archipelago.

A major characteristic of Nanboku-cho combat was the prevalence of "kachikusa" (foot combat). Unlike battles from the late Heian through Kamakura periods, which idealized mounted single combat between samurai, Nanboku-cho battles featured armies primarily composed of foot soldiers including ashigaru. Against densely packed foot soldiers, the sweeping and overhead blows leveraging the long blade's centrifugal force proved extremely effective, dramatically increasing demand for odachi.

Notable battles of this era include the Battle of Minato River (1336) and the Battle of Shijō Narawate (1348), and the battle scrolls of these conflicts depict samurai wielding odachi. Numerous accounts tell of southern commanders including father and son Kusunoki Masashige and Kusunoki Masatsura favoring odachi.

In major production centers such as Bizen, Soshu, Yamato, and Mino, renowned smiths competed in crafting odachi. The Osafune school smiths Kanemitsu and Chōgi, and the successors of Soshu-tradition Masamune, left masterworks of odachi from the Nanboku-cho period, and most odachi designated as national treasures or important cultural properties date to this era. Once combat methods shifted after the Muromachi period, odachi production declined sharply, replaced by the more mobile uchi-gatana as the mainstream weapon. The Nanboku-cho era was truly the golden age of odachi.

Combat Application

Actual combat use of odachi has been subject to considerable debate owing to weight and length. Three primary methods of use are considered.

• Mounted cavalry use: A mounted warrior delivers massive overhead blows to strike the head or shoulders of foot soldiers or mounted enemies in single blow. Since such weapons could not be worn at the waist when mounted, they were either propped against the saddle's front bow or carried by an attendant and handed to the rider immediately before engagement. The height of the mounted position combined with the force of the overhead blow maximized the weight advantage of the odachi.
• Collective use as a hafted weapon: Similar to the tactical principles governing spears and naginata, the long blade could be regrasped like a "haft" and used in group combat with horizontal sweeping strokes. Special grip methods unknown in ordinary sword combat—such as "sakate mochi" (reverse grip) or "morote zuki" (two-handed thrust)—are passed down in some schools as nodachi technique.
• Use for psychological intimidation: A general renowned for valor simply appearing with an odachi slung across the back could psychologically pressure opponents. War records from the Sengoku period contain frequent descriptions such as "a tall man bearing an odachi on his back," and the combined "martial presence" of physique and odachi sometimes produced more psychological effect than the actual blow.

Such specialized nodachi techniques were systematized into schools in later ages. Yakumarū-ryū (also called Nodachi-Jiken-ryū) is a system of nodachi technique transmitted in Satsuma Domain, characterized by audacious technique of drawing back dramatically before delivering a decisive overhead slash, and was widely known as the formidable swordplay of samurai of the late shogunate era. Shinkage-ryū, systematized by Kamiizumi Nobutsuna, incorporated into nodachi technique the management of distance and control of position utilizing the long blade, influencing many subsequent sword schools.

However, wielding odachi exceeding 3 shaku in daily combat was physically and functionally extremely difficult, and many examples created as "votive blades" for religious purposes were never used in actual combat.

Votive Odachi: Sacred Swords Offered to Shrines and Religious Meaning

A considerable portion of surviving odachi were produced as votive offerings to shrines and preserved as such. Prior to deployment, to give thanks for victory, or as objects of prayer for spiritual affliction, warlords and powerful figures presented large swords to shrines. Offering a larger blade than ordinary votive swords was understood to demonstrate deeper faith and resolve.

In Japanese Shinto tradition, the sword has long been regarded as a "yorishiro" (a vessel for divine spirit). The belief that larger swords house more powerful spiritual force connects deeply with the religious motivations underlying odachi offerings. The practice of swords being enshrined as the object of worship at shrines throughout the country derives from this ancient understanding of the sword as a medium between the human and the divine.

Itsukushima Shrine (Hiroshima) is known as a shrine with ties to the Heike clan, and numerous warlords beginning with Taira no Kiyomori offered swords there. Votive sword collections including blades traditionally attributed to donations by Minamoto no Yoritomo are designated national treasures or important cultural properties, and include several odachi.

Kasuga Grand Shrine (Nara) has been revered by the warrior class since the Heian period as the tutelary shrine of the Fujiwara clan. The Kasuga Grand Shrine National Treasure Museum, on the shrine grounds, houses a large collection of tachi and odachi from the Heian through Muromachi periods, making it one of Japan's largest sword collections. The holdings include several odachi from the Nanboku-cho period, preserving the highest technical standards of the age.

Ōyamazumi Shrine (Ehime, Ōmishima) has been revered since antiquity as the head shrine venerating all mountains and seas throughout the nation. Successive powers—the Genji, Heike, the Kamakura shogunate, and the Muromachi shogunate—competed in offering martial equipment. Currently housing over 100 designated national treasures and important cultural properties, it is called "Japan's foremost martial equipment collection." Several odachi from the Nanboku-cho period survive, allowing the forging techniques of the era to be understood from the maker's signatures and the shape of the hi (grooves) carved into the blade.

Surviving Masterworks

Sword with signature "Bizen Osafune resident Kanemitsu" is counted among the highest achievements in Nanboku-cho odachi. Kanemitsu was a representative swordsmith of the Osafune school in Bizen, producing numerous odachi during the Nanboku-cho upheaval. Characterized by powerful sword form and brilliant irregular hamon, it conveys the intensity of the era as if the passion of the time had been sealed within iron and steel.

Furthermore, in large swords forged by Osafune Nagamitsu and Kanemitsu, the quantity of tamahagane employed was said to be 2–3 times that of a normal tachi. Since quality tamahagane obtained from a single tatara operation is limited, forging a single odachi required careful selection and combination of materials from multiple smelt cycles, demanding procurement systems differing from the norm. Furthermore, among votive odachi surviving at Ōyamazumi Shrine and Kasuga Grand Shrine, specimens with blade length exceeding 150cm have been confirmed, drawing ongoing scholarly attention as masterworks pushing the boundaries of period forging technology.

Sword with signature "Chōgi" is attributed to Chōgi, said to be among the Ten Virtuous Disciples of Masamune, and is notable for the vigorous irregular hamon influenced by Soshu tradition. Records attest ownership by the shogunate and guardian daimyo of the highest rank, with the succession of proprietors mirroring the power transitions of medieval Japan.

Sword with signature "Kunimune" and other fine surviving Nanboku-cho odachi by renowned smiths of Bizen and Soshu are frequently displayed in special exhibitions at the Tokyo National Museum and Kyoto National Museum, conveying to contemporary viewers the overwhelming sculptural beauty of the period.

Japan's Largest Surviving Odachi: The Tarō Tachi and Shida Odachi

Among surviving odachi, two examples are widely known and have had their blade lengths precisely measured, each possessing blade length exceeding three times that of a standard tachi, concretely conveying the scale of odachi.

The Tarō Tachi is a colossal odachi held at Atsuta Shrine (Nagoya), with blade length of 221.5cm, overall length of 303cm, and weight of approximately 4.5kg. The blade bears the signature "Sueno Aoē" and is transmitted as the work of the Bizen Aoē school. It is renowned in tradition as the weapon wielded by the valiant Magara Naotaka of the Asakura forces at the Battle of Anegawa (1570), and is displayed at the votive treasure exhibition facility "Kusanagi-kan, Treasure House of Swords," which opened in 2021.

The Shida Odachi is an odachi held at Yahiko Shrine (Yahiko Village, Niigata Prefecture), with blade length of 220.4cm and overall length of 322.2cm, designated an Important Cultural Property of Japan. The tang bears a date of Ōei 22 (1415), and tradition holds it was forged by Iemori, a swordsmith of Osafune in Bizen, and offered by Shida Saburō Sadashige, lord of Natsudo Castle in Echigo. As a curved blade, it holds the distinction of being the longest among swords designated Important Cultural Property or National Treasure.

An even longer example exists: the "Haja no Omtachi" (Sacred Sword of Evil-Repelling) held by Hanaoka Hachimangu Shrine in Yamaguchi Prefecture, with blade length of 345.5cm, known as Japan's longest sword. However, this was a specially forged large votive blade offered during the late shogunate (Ansei era) for prayer, differing in character from practical-use odachi. The existence of such record-breaking great blades testifies to how far Japanese sword-forging technology was pushed to its limits.

Suriage: The Reborn Lives of Odachi as Tachi and Uchi-gatana

As combat methods transitioned after the Sengoku period from mounted warfare to foot-soldier-based collective combat, the unwieldiness of odachi became increasingly apparent. As a result, the technique of "suriage" (resharpening)—shortening the tang of the odachi or sometimes reducing blade length itself to refashion it as a normal tachi or uchi-gatana—became widely practiced during the Sengoku period.

Suriage changes a sword's dimensions and purpose while the hamon and jihada quality are inherited unchanged. In other words, the steel and hamon forged by Nanboku-cho master smiths could be enjoyed in more manageable proportions—a practical benefit. When suriage was performed, the tang became shorter and the original signature might be lost. When the signature is preserved, it is treated as "large suriage, no signature," and in sword evaluation is typically ranked lower than the original.

One reason relatively few odachi survive is this historical circumstance of "conversion to practical use." Blades originally odachi are often currently classified as ordinary tachi or uchi-gatana. For this reason, in research into sword provenance, discerning the traces of suriage becomes an important task in reconstructing the original manufacturing intent and distribution history of the period.

Conclusion: What Odachi Tell Us

Odachi and nodachi represent a crystallization of Japanese sword beauty and function in extreme form. The contradiction that they exceed practical handling while achieving uniform hardened edges across their entire length through meticulous forging technique raises fundamental questions about the boundary between utility and art in Japanese sword culture.

Generated by the turmoil of the Nanboku-cho era and preserved within the sacred precincts of shrines, odachi are the most direct evidence that swords transcend their role as weapons to become cultural properties bearing spiritual and religious significance. The prayers, martial authority, and beauty cast into iron and steel—through their overwhelming physical presence, odachi continue to convey to us the very atmosphere of their age.

Related Columns: Large Swords and Field Swords of the Nanboku-cho Era | Field Swords and Large Swords: Combat and Faith | Tamahagane and Tatara Ironmaking