Independent Japanese watchmaker Jiro Katayama, following the GPHG Petite Aiguille nomination for his No. 5 KAI, has unveiled his latest creation: the Ōtsuka Lōtec No. 9. Encased in a 44mm x 30mm rectangular stainless-steel frame, the watch blends industrial design with high horology. Its right-side dial showcases stacked hour and minute discs, illuminated by a luminous block for low-light visibility, while a gently curved steel caseback and 26mm-lug calfskin strap ensure ergonomic comfort.
Five Complications in Motion
At the top of each hour, three mechanisms animate in precise synchrony. The jumping-hour disc advances instantly, the retrograde minute disc snaps back to zero via a central hairspring, and a hammer strikes a pipeline-shaped gong to produce a crisp chime. Below, an offset tourbillon rotates gracefully, complemented by a slim indicator tracking the watch’s 40-hour power reserve.
The No. 9 is powered by the in-house Cal. SSGT, a manual-winding movement comprising 278 components, including 30 jewels and five ball bearings. Custom 2.5mm ruby bearings and the world’s smallest 1.5mm steel bearings, supplied by MinebeaMitsumi, reduce friction and enhance precision on the hour-disc shaft and hammer pivot.
Katayama explains, “I wanted to design a wristwatch that, much like an induction electric meter, reveals its inner mechanical parts in motion. With No. 9, every moving component under the sapphire crystal evokes industrial machinery — its textures, vibrations, and sounds.”
Availability and Pricing
Water-resistant to 3 ATM, the No. 9 is priced at ¥17,600,000 JPY (tax included, approx. $118,890 USD). Made in Japan and covered by a one-year warranty, it is available exclusively through Ōtsuka Lōtec’s official website.




