Our Heritage
About Abyssal Moon Thread
Nearly five decades of unbroken practice, seven master smiths, and more than 1,200 certified blades — forged in the heart of Kyoto.
Founded in Fire — 1978 to Today
Abyssal Moon Thread was established by master smith Hiroshi Tanaka in 1978 in the Higashiyama district of Kyoto — a neighbourhood that has housed artisans for centuries and whose narrow streets still echo with the sound of hammer and chisel.
Hiroshi Tanaka trained for eleven years under the late National Living Treasure smith Yoshindo Yoshihara in Tokyo before returning to his native Kyoto to establish his own forge. He brought with him not only technique but a philosophy: that a sword is not finished when the edge is sharp, but when every element — steel, geometry, polish, fittings — forms a unified aesthetic and functional statement.
In the early years, the workshop produced only a handful of blades annually. Word spread slowly through the tight-knit world of nihonto collectors and martial arts practitioners. By the late 1980s, a waiting list had formed. Today, with seven resident smiths working under Hiroshi's direction alongside his son and successor Kenji Tanaka, the workshop accepts approximately 60–70 commissions per year — still a small number by industrial standards, but one that preserves the necessary depth of attention each blade deserves.
We were designated a Traditional Craft Studio by Japan's Agency for Cultural Affairs in 2002. In 2019, the NBTHK awarded our work a special commendation for consistent quality across multiple inspection periods. These are not credentials we display as marketing — they are the natural result of doing the work properly, year after year.
A Note on Tradition and Evolution
We use no power hammers, no CNC grinding, and no commercially produced steel. The choice is not nostalgic — it is metallurgical. The properties that make a nihonto extraordinary arise precisely from the imperfections, the variations, and the human sensitivity that only hand work can introduce. We are not preserving a tradition because it is old; we preserve it because it is still the best way to make a great sword.
Our Master Smiths
Seven craftspeople — each with a minimum of a decade of dedicated training — form the core of our workshop.
Hiroshi Tanaka
48 years in the craft. Student of National Living Treasure Yoshindo Yoshihara. Specialist in suguha and notare hamon in the Yamashiro and Soshu traditions.
Kenji Tanaka
Trained under Hiroshi from age 16. NBTHK prize recipient 2018. Known for exceptional choji hamon work and complex kissaki geometry on nodachi-length commissions.
Yuko Shibata
One of only a handful of female togishi working in Japan today. Trained in Nagoya under master polisher Takeshi Ogawa for 14 years. Her work is celebrated for revealing unusually deep nie activity in the hamon.
Certifications and Recognitions
Our commitment to quality has been acknowledged by Japan's leading cultural institutions and preservation bodies.
Agency for Cultural Affairs Designation (2002)
Abyssal Moon Thread was formally designated as a Traditional Craft Studio by Japan's Agency for Cultural Affairs in 2002. This status recognizes that our work meets rigorous standards for authenticity of technique, transparency of materials, and contribution to the preservation of Japanese cultural heritage. The designation entitles our craftspeople to participate in heritage development programmes and brings our work into dialogue with conservation institutions across Japan.
NBTHK Commendations (2014, 2018, 2023)
The Society for the Preservation of Japanese Art Swords (Nihonto Bijutsu Kyokai) has awarded our workshop commendations for consistency of quality across multiple inspection periods. In 2018, our lead smith Kenji Tanaka received an individual prize for exceptional technical mastery in complex hamon work. These are not marketing claims — they are independent verifications of our craft, earned through rigorous testing of our blades by Japan's leading nihonto experts.
International Client Base
Our work is held in private collections across North America, Europe, and Asia. Museums including the Metropolitan Museum of Art (New York) and the Philadelphia Museum of Art have acquired example pieces for study collections, where they are accessible to researchers and students of metallurgical history. This international placement reflects both the technical quality and the cultural significance of our work.
Milestones in Four Decades
From a single smith to a recognized institution — the arc of Abyssal Moon Thread's growth while maintaining uncompromising standards.
Foundation
Hiroshi Tanaka establishes the workshop in Higashiyama, Kyoto, after completing his apprenticeship under National Living Treasure Yoshindo Yoshihara in Tokyo. First blade produced: a suguha katana, still held in Tanaka's personal collection.
First Apprentices
After seven years of solo work, Hiroshi begins training his first formal apprentice. The workshop expands from single-room operation to a two-room structure with dedicated folding and polishing areas. Annual output rises from 4 to 12 blades.
International Recognition
A blade forged by Hiroshi Tanaka is featured in a major retrospective on contemporary nihonto at the Tokyo National Museum. A collector from New York commissions the first of many blades for American clients. The waiting list, previously informal, is officially established as a formal queue.
Cultural Affairs Designation
Abyssal Moon Thread receives formal recognition from Japan's Agency for Cultural Affairs as a Traditional Craft Studio. This milestone marks our transition from a private atelier to an institution of cultural importance. The workshop becomes a destination for visiting scholars and heritage researchers from around the world.
Succession Generation
Hiroshi's son, Kenji Tanaka, completes his formal training and becomes a resident smith in the workshop. For the first time, the workshop operates with true specialization: Hiroshi overseeing strategy and advanced work, Kenji leading the forging stage, and Yuko Shibata (togishi) overseeing polishing. Team size reaches seven craftspeople.
1,000 Blades Milestone
The workshop celebrates the completion of its 1,000th commission. Cumulative pieces submitted to NBTHK for certification number over 800, with an exceptional certification rate of 96%. The milestone blade — a nodachi for a major Japanese museum — receives special NBTHK recognition for technical achievement.
Continuing Tradition
With nearly five decades of unbroken practice, the workshop forges 60–70 blades annually, each a direct expression of the master smiths' accumulated knowledge. The waiting list extends 3–4 years, ensuring that each blade receives the depth of attention it deserves. Our mission remains unchanged: to produce swords that honor the past and serve the future.