Brief History

In 2025, this project began.

Since then, we have collected many materials, literature and visual records concerning antique Japanese wadokei.

A primary foundational text is the "Karakuri-zui" (Illustrated Machinery 機巧図彙), published in 1796. This remarkable book features exquisitely detailed illustrations, making the mechanics of wadokei exceptionally accessible. A modern Japanese translation by Kazuo Murakami, published in 2014, has also made this treasure trove of knowledge readily available.

However, as noted earlier, this book deals only with single-foliot wadokei, meaning it is not sufficient for resurrecting the dual-foliot system. It is the dual-foliot mechanism—the zenith of Edo-period Japanese technology—that's our aim to revive.

Another useful text is "The Research of the Wadokei in the Edo Period" by Yamaguchi Ryuji, published in 1947. It is remarkably detailed, featuring illustrations of various mechanisms, but it is very old and in poor physical quality. Published shortly after the war, such books suffered from low-grade paper, reflecting severe shortages of quality materials, as well as printing machinery and techniques lost during the conflict. Fortunately, the National Diet Library makes its digital images available online, rendering this book our essential guide for resurrecting antique wadokei.

Another invaluable reference is "A Collection of Japanese Clocks", written by N.H.N. Mody and published in 1932. Mody, a wealthy merchant residing in Kobe, amassed a vast collection of wadokei before the war. Tragically, his entire collection was lost during the air raid on Kobe in 1945. However, the Japanese translation of this book is published in 1932 and its digital image is also availabe online. My mother worked as a nurse in Kobe and encountered the bombing and lost her workplace.

In addition, numerous other horological publications have provided us with vital assistance.

Designing and Making Wadokei

We strive to replicate the construction of traditional antique wadokei as faithfully as possible. However, adhering strictly to ancient methods presents a significant disadvantage in terms of cost and efficiency.

In former times, components were crafted primarily from brass and iron. Gears and arbours were cut and polished by hand or using primitive lathes—a process demanding an immense investment of time and arduous labour, which is neither commercially viable nor practical today. If we were to do so, the cost would easily exceed JPY 10 to 20 million(USD 60,000 to 130,000)!

Consequently, we have chosen to fabricate the necessary components using contemporary manufacturing technologies. While paying great respect to the  ancient designs and principles, we utilise 3D CAD systems, 3D printers, laser cutting and engraving machines, alongside human-operated lathes.

Furthermore, we have replaced the hand-filed, primitive gears of the Edo period with modern industrial involute metal gears to ensure smooth operation and significantly extend the lifespan of the mechanism. Hand-filing gears is exceptionally time-consuming and labour-intensive. More importantly, it is impractical for modern use, as Edo-period handcrafted gears often lacked optimal tooth geometry and suffered from severe wear. In contrast, industrially manufactured gears offer superior performance and efficiency while being readily available. We therefore employ them, whilst paying our utmost respect to the ingenuity and labour of the ancient artisans.

Additionally, regarding the springs used in the mechanism, we employ two coil springs rather than the traditional leaf springs.

In the Edo period, steel was not readily available, as Japan lacked the technology for large-scale industrial steel production. Consequently, crafting fine leaf springs from scratch, low-quality steel would have been exceedingly difficult. Furthermore, attempting to forge and shape bulk steel into traditional flat springs—often requiring delicate drilling and piercing—presents significant technical hurdles and material risks today.

Instead, modern coil springs are readily available, highly reliable, and allow us to ensure the smooth operation of components such as the click (kohaze-guruma) and winding drum (itomaki-guruma). While deviating from historical material authenticity in this specific detail, we believe it is a necessary and pragmatic choice to guarantee the longevity and reliability of the timepiece, while maintaining the utmost respect for the original design principles.

Procurement of materials

Indeed, we design the wadokei by ourselves, but we don't make everything from scratch.

Of course, Edo-period clockmakers (tokei-shi) did not manufacture every single component from raw ore. Refined copper, steel stock, and unworked metals were supplied by regional refineries and specialized blacksmiths. Similarly, the heavy lead weights that powered the clock mechanisms were provided by local foundry masters and casters.

Now, we have a lot of online manufacturers around us, so we placed orders of some materials on these suppliers.

We asked some professional artisans and suppliers in Japan. Since we are proud of making wadokei through Japanese technology and tradition, we exclude other Asian manufacturers. We provide truly made in Japan wadokei to you.