At first glance, you may think the above watch is from the Swiss watchmaker Urwerk, known for its sci-fi-infused timepieces with satellite hours displays and retrograde minute tracks. However, the creation in question is from none other than Otsuka Lotec, an independent Japanese firm around since 2008 but not as well known outside of its home country.
Founded by self-taught watch designer Jiro Katayama, Otsuka Lotec has now added a new No.5 model to its catalog, following the No.6 and No.7.5. Confused? Let’s take a look…
The Same in Name Only
The new No.5 KAI might share a name with its progenitor, launched over a decade ago, but is different in design and function, among other things. Featuring a similar design ethos, the old No.5 (sans KAI) was a regulator watch with rotating hour and minute discs on the top and bottom of the dial, respectively.
As for the 2025 refresh of the No.5, Otsuka Lotec sports a wandering hours display, meaning it features three cruciforms, each with four numerals on the stems. The current hour moves along a 120-degree arched minute track on the right side of the dial, from 00 to 60. And as the hour comes to a close (e.g., 5:59), the following hour (in this case, 6) starts the cycle up top. Also, the bottom of the dial features a ticking seconds disc.
Thin to Win
Measuring 40.5mm across, the actual industrial-styled stainless steel case is a measly 7.6mm in thickness. However, with the protruding box sapphire crystal, the overall thickness gets up to 12.2mm. These types of watches tend to be rather thick, but Otsuka Lotec wanted theirs to have more practical wearability and legibility, hence the thinness and box crystal. It had help from a pair of custom MinebeaMitsumi ball bearings, including one that’s the smallest in the world. You can see them on the dial itself. Powering this in-house wandering hours module is a Miyota 90S5 automatic movement offering 40 hours of power reserve, kept behind the closed steel caseback. Lastly, the watch is adorned with a black leather strap.
Spec Sheet
Case Size: 40.5mm
Case Thickness: 12.2mm
Case Material: Stainless steel
Water Resistance: 30m
Movement: Miyota 09S5 automatic with wandering hours module
Band: Black leather strap
Limited Edition?: Yes, unspecified
Pricing & Availability
Offered via lottery in March, the No.5 KAI will be limited to an unspecified edition size and priced at JPY 748,000 (~$4,811). Head over to Otsuka Lotec’s website to learn more.
Recap
Otsuka Lotec No.5 KAI
Otsuka Lotec evolves its old No.5 with this new version featuring a wandering hours complication.
