VOL.215 MAY 2026
[SPRING SPECIAL ISSUE] ENJOYING JAPAN’S SPRING BY LOCAL TRAINS [Introducing Precious Traditional Japanese Culture to the World] Forging a Supreme Blade with Techniques Preserved for 700 Years—The Essence of Japanese Culture in Uncompromising Discipline

Johan Leutwiler, the first katana-kaji, or swordsmith from outside Japan, works on an ongoing basis to craft Japanese swords. We spoke with Johan about the essence of Japanese culture reflected in the Japanese sword, a tradition that has been passed down without interruption for more than 700 years.

I believe the value of the Japanese sword lies in its rarity as a traditional craft. Looking beyond Japan, there are very few traditions that, like the Japanese sword, have been continuously passed down for nearly a thousand years while preserving both their techniques and spiritual foundations. From my understanding, this rarity is precisely why Japanese swords are so highly regarded overseas.

As modern tosho,³ we craft swords as works of art. Drawn to the craft of sword-making, I came to Japan and became a swordsmith. I believe many people from overseas share the same aspiration. In today’s society, few works are created with such meticulous care. Swordsmiths forge many blades, yet release only the finest one into the world. The rigor of this process, the resolve it demands, and the values it embodies resonate deeply with many foreign audiences. It is precisely in this approach that the essence of the sword as a work of art lies.  

In modern Japan, the Japanese sword is often seen as something old-fashioned. Images of sword fights in period dramas tend to dominate people’s perception, and I feel that the artistic value and spiritual essence of the Japanese sword are not always fully conveyed. A Japanese sword is not merely a weapon—it embodies Japanese culture itself.

In Europe and other regions overseas, there is a long-standing tradition of appreciating crafts as works of art. The fact that the techniques of the Japanese sword, passed down for 700 years, are still faithfully preserved and reproduced may help explain why this tradition resonates so deeply with foreign audiences today. The shape of a sword, its sori (curvature), the jigane⁴ (steel texture), and its hamon⁵ (temper pattern) vary by period, each carrying the spirit of its time. Many foreigners study these differences with great enthusiasm. The process of making a sword and the specialized terminology associated with it offer countless clues about the aesthetic sensibilities and values of the Japanese people of the era.

Japanese culture has the power to move people’s hearts, regardless of nationality. If through the Japanese sword, people can experience even a glimpse of that depth and develop an interest in it—that is the greatest joy I can have as a swordsmith.

Johan Leutwiler
Born in Switzerland. Seeing Japanese swords at an exhibition at age 17 and being captivated by their beauty inspired his aspiration to become a swordsmith. After coming to Japan in 2017 and training as an apprentice for five years, he became the first foreigner to obtain national certification as a katana-kaji in 2024. After becoming an independent swordsmith, he established a workshop in Hiroshima Prefecture and received the Achievement Award (First Place) and New Face Award in the Sakuto (Blade Forging) division at the 2025 Contemporary Swords and Artworks exhibition. His swordsmith name is Mitsutsuna.
Photo: KUDO Asuka

• 1. Steel made by smelting iron sand, used as the raw material for a Japanese sword.
• 2. The process of heating metal and applying force to transform its shape. Also called tanzo.
• 3. Another word for katana-kaji, or swordsmith.
• 4. To bring out strength and resilience, the steel used to make a Japanese sword is repeatedly folded and hammered in a process called folding and tempering (tanren). This process produces patterns on the blade’s surface, known as the steel’s texture, or jigane.
• 5. A white wave-like pattern added during hardening, one of the processes of making Japanese swords, in which the steel is hardened by cooling it rapidly from a high-temperature state. 
• 6. The part of a Japanese sword corresponding to the handle is called a kozuka, and the blade portion is called a kogatana. In some cases, the term kozuka may refer to the entire small sword, including the kogatana. These are slender, short blades, primarily decorative rather than practical.

By Johan Leutwiler
Photo: KUDO Asuka