The Showa Legacy in Modern Swords: How Postwar Revival and Living National Treasure Smiths Forged an Unbroken Chain of Tradition

Fear of Technical Discontinuity — Until the Reopening in 1953

From the end of the war in 1945 (Showa 20) until the authorization of new sword manufacturing in 1953 (Showa 28), for approximately eight years, sword makers were unable to legally produce new blades. The "Sword Manufacturing Prohibition Order" issued by GHQ encompassed not only the production of swords as art objects, forcing many sword makers to change occupations to make a living. Many smiths sustained themselves by producing agricultural tools and equipment, while others turned to charcoal burning or farming.

This period is also called the "gap period in Japanese sword manufacturing technology," and many stakeholders felt a sense of crisis that "traditional techniques might be lost." Forging techniques are an accumulation of embodied knowledge that is difficult to verbalize, and closing a workshop could mean the death of the craft.

However, in reality, the maintenance and transmission of techniques continued beneath the surface. Elderly sword makers secretly transmitted their skills to young apprentices, and records of used whetstones and quenching clay formulations were carefully preserved. Some sword makers maintained their furnaces under the guise of making knives and farm tools, never losing their sense of the forging craft. While maintaining outward silence, those who continued to pass down their knowledge before the forge to the next generation became the foundation for the postwar revival of Japanese sword culture.

1953 (Showa 28) — The Sword Makers' Fresh Start

When new sword manufacturing was authorized in the same year as the Firearms and Swords Law took effect (1953, Showa 28), the elder sword makers returned to their workshops and began swinging their hammers again. But the problem was not limited to personnel. Because the supply of tamahagane had been cut off, many sword makers were forced to use substitute steel materials—rail steel and special machine steel. While these materials were uniform and easy to work with, they could not produce the fine jihada and ji patterns unique to tamahagane, and sword enthusiasts sometimes criticized them as "not authentic."

In 1957 (Showa 32), the "Japanese Sword Masterworks Exhibition" was held under the direction of the NBTHK, and public evaluation of modern sword quality after production resumed took place. The exhibition encouraged contemporary sword makers while also highlighting the challenge of standardizing quality levels. Outstanding works selected through judging served as proof to society that technical knowledge was indeed being transmitted, and instilled in young sword makers a strong sense of competition and pride.

The Revival of Tatara and the Resurgence of Tamahagane Production

The greatest technical challenge in the revival of modern swords was securing tamahagane. During the wartime and postwar chaos, traditional tatara iron smelting had effectively ceased, and the specialized craftsmen known as "murage" who understood the process were aging and dwindling in number.

In 1957 (Showa 32), test operations of the "Nihon Tosho Tatara" began in the Okiusumo region of Shimane Prefecture. This project, led by the NBTHK, was an unprecedented attempt from the perspective of cultural property preservation to recreate the ancient tatara iron smelting technique using only iron sand and charcoal. Producing kera (iron chunks) through the traditional method of maintaining the furnace for three days and three nights, and then separating out tamahagane for sword makers, required artisanal skills entirely different from modern industrial iron smelting.

Around 1977 (Showa 52), a regular operating system was established, and thereafter tamahagane has been produced through annual operations. The revival of Nihon Tosho Tatara was not merely about securing materials. Because tamahagane has non-uniform carbon content, the "tsukuri" technique of separating and combining it into kawagane (skin iron) and shingane (core iron) through forging comes alive. This technique is the foundation that produces the unique properties of the Japanese sword—"supple, unbreakable, unbendable, and sharp"—and a true Japanese sword cannot exist without tamahagane. As of 2026, Nihon Tosho Tatara continues to operate 1-2 times annually, maintaining a stable supply to domestic sword makers.

Living National Treasures Sword Makers — Giants Born in the Showa Era

Among sword makers active during the Showa era, several were designated after the war as holders of Important Intangible Cultural Properties (Living National Treasures). All had overcome the trials of the military sword era and the gap period of the manufacturing ban, and their designation was an evaluation of both technical excellence and their will to transmit knowledge across generations.

Gassan Sadaichi (2nd generation) (Designated: 1970, Showa 45) — An Osaka sword maker who lived from the Meiji through Showa eras. He continued to uphold the Gassan school's distinctive "ayasugi-hada"—complex surface patterns reminiscent of ripples on water. He is known for maintaining traditional forging methods against the demands for uniformity and mass production required by military sword manufacturing, and his spirit has been passed down to the current Gassan Sadatoshi.

Miyairi Yukihira (Designated: 1977, Showa 52; passed away the same year) — A Nagano sword maker. Building on the traditions handed down in Shinshū, he worked to recreate the ji-metal of ancient swords and was an iconic figure in the Showa sword world, actively involved in tatara revival. He devoted himself to training disciples until his final years, and his techniques were inherited by Miyairi Kozaemon Yukihira.

Sumitani Masamine (Designated: 1971, Showa 46) — From Kōchi. He is highly regarded for establishing a unique "composite lamination" forging technique—a method of stacking multiple layers of steel with different carbon contents—which dramatically elevated the technical standards of postwar modern swords. Sumitani's sword-making philosophy was permeated with the belief that "beauty and cutting edge come from the same source," and he transmitted this philosophy along with his techniques to his disciples.

The techniques these master craftsmen developed during the difficult Showa era function as a living textbook for today's sword makers.

The Chain of Master and Apprentice — The Lineage of Technique Continuing from Showa to Reiwa

The greatness of Living National Treasure sword makers lies not only in the beauty of their works. The "chain of master-apprentice relationships" extending from the disciples they cultivated to the disciples those disciples cultivated forms the essential strength of contemporary Japanese sword culture.

In Japanese traditional crafts, techniques are not transmitted through writing. The temperature of the furnace is read by the "hi-iro" (color of the fire), the timing of quenching is judged by the "mizu-oto" (sound of the water), and the condition of the steel is sensed through the weight and rebound of the hammer. These can only be mastered by standing beside the master in front of the furnace for many years. The Living National Treasure sword makers of the Showa era transmitted this embodied knowledge to the next generation through one-on-one master-apprentice relationships.

As many contemporary renowned sword makers say, "I still remember the sound of my master's hammer," the technical sensibility born in the Showa forges remains in the air of workshops in the Reiwa era. Within a single sword blade, the hand memories of multiple generations are layered together.

Contemporary Evaluation of Showa Traditional Forged Swords

Swords crafted using traditional methods during the Showa era are highly valued in the modern sword market. Works by Living National Treasures, as well as pieces by appointed sword masters (smiths with the skills of the Meiji and Taishō eras who were active in the Showa era), frequently command auction prices exceeding several million to over ten million yen.

The basis of this evaluation lies not in "age" but in both technical perfection and historical context. The posture of sword makers who resisted the demands for mass production of military swords, or who persevered through the gap period of manufacturing bans, and continued to forge without compromise, resonates strongly with modern enthusiasts.

Additionally, Living National Treasure works from the Showa era have the practical advantage that while their numbers are limited, documentation is well-maintained, making it easy to verify provenance. Through preservation society examination records and exhibition catalogs, it is often possible to trace the year of creation, steel used, and quenching techniques, making them highly valuable as research materials.

The techniques and spirit that Showa traditional sword makers protected with their lives support the foundation of contemporary Japanese sword culture. Their legacy exists in the form of works in the hands of enthusiasts both domestic and abroad, and continues to live in active workshops in the form of their disciples. When contemplating a single sword blade, modern viewers must not forget that the struggles and pride of the Showa era are reflected in that blade. Japanese Sword Column Index provides more detailed information about the history and techniques of these sword makers.