After winning the Challenge Prize at GPHG 2024 with the retrograde-powered No. 6, Tokyo-based watchmaker Jiro Katayama has thrown caution to the wind. His latest creation abandons the affordable Miyota-based formula that built his cult following and ventures into uncharted territory with an entirely in-house movement. The result is the Ōtsuka Lōtec No. 9 — a rectangular powerhouse that combines jumping hours, rewinding minutes, a tourbillon, hour striking, and power reserve indication in a surprisingly compact package.
Nine Years in the Making
Katayama has been developing the No. 9 for nearly a decade, and it shows in every considered detail. Affixed with a black calfskin leather strap, the rectangular stainless steel case measures just 44mm x 30mm with a maximum thickness of 13mm, yet houses 278 components within its Cal. SSGT manually-wound movement. That nomenclature comes from Katayama’s observation that layering complications on the main plate resembled placing sushi on a wooden geta (“Su-Shi-Ge-Ta” shortened to SSGT).
On the case, a wrap-around sapphire crystal reveals the industrial ballet happening inside, while a distinctive pipeline-shaped gong snakes along the left side of the case like exposed wiring in a power plant.
Industrial Symphony
At the top of each hour, three mechanisms spring into synchronized action. The transparent hour disc makes its instantaneous jump, backlit by embedded luminous blocks for low-light readability. Simultaneously, the rewinding minutes disc — driven by a central hairspring — snaps back to zero with the precision of an analog gauge. Then comes the sonic punctuation. A large hammer strikes that serpentine gong, producing what Katayama describes as a “crisp, industrial chime.”
The offset tourbillon at 6 o’clock regulates the 18,000 vph movement, supported by custom MinebeaMitsumi ball bearings that include the world’s smallest at just 1.5mm in diameter. Even the power reserve gets the industrial treatment, displayed as a slim cylinder that retracts as energy depletes.
Spec Sheet
Model: Ōtsuka Lōtec No. 9
Case Size: 44mm
Lug-to-Lug: 30mm
Case Thickness: 13mm
Case Material: 316L stainless steel with wrap-around sapphire crystal
Movement: In-house Cal. SSGT, manual-wind
Functions: Jumping hours, rewinding minutes, tourbillon, hour striking, power reserve
Power Reserve: 40 hours
Water Resistance: 30m
Strap: Calfskin leather
Pricing & Availability
About 20x more expensive than the brand’s previous models, the No. 9 is priced at ¥16,000,000 (~$108,000). True to Ōtsuka Lōtec tradition, availability remains limited to Japan with no official international distribution. Production numbers haven’t been announced, but expect extremely limited quantities given the complexity and Katayama’s artisanal approach.
Recap
Ōtsuka Lōtec No.9
Tokyo watchmaker Jiro Katayama abandons his affordable formula with the Ōtsuka Lōtec No. 9, packing five complications including a tourbillon and hour strike into a compact rectangular case for $108,000. After nine years of development, this industrial-inspired timepiece is a big leap from sub-$5,000 pieces to haute horlogerie territory, available exclusively in Japan.
