Introduction
Founded by Japanese industrial designer Jiro Katayama in 2008, Otsuka Lotec has become one of the most original voices in contemporary independent watchmaking. Drawing inspiration from industrial machinery, gauges and precision engineering rather than traditional Swiss horology, the brand has developed a devoted following thanks to its unconventional displays and exceptionally low production numbers. International recognition arrived in 2024 when Otsuka Lotec received the Challenge Watch Prize at the Grand Prix d'Horlogerie de Genève (GPHG), cementing its status as one of Japan's most exciting independent manufactures.
The No. 7.5 perfectly encapsulates the brand's philosophy. Featuring a regulator-style display with retrograde minutes and jumping hours housed within an architectural stainless steel case, it transforms a familiar automatic movement into something entirely unique through an ingenious proprietary display module. Produced in extremely limited quantities and rarely seen outside Japan, the No. 7.5 is a compelling example of mechanical creativity unconstrained by convention.
Loupe This Scorecard
Grade
M 10
Status
Vetted & Approved
Included
Box and papers
Est. value range
$4,000 – $6,000
The Details
Brand
Otsuka Lotec
Dimensions
40mm
Model
No. 7.5
Movement
Automatic Miyota calibre 82S5 with jumping-hour module
Reference
7.5
Bracelet
Leather strap
Year
2025
Condition
New
Material
Stainless steel
Included
Box and papers
Dial Color
Silver
THE DIAL
The No. 7.5 abandons the traditional dial entirely in favour of a striking mechanical display inspired by industrial measuring instruments. A retrograde minute indication dominates the upper half of the watch, while the jumping hour is displayed through a rotating aperture below, creating a display that is both highly legible and unmistakably Otsuka Lotec.
THE CONSTRUCTION
The brushed stainless steel case reflects the brand's industrial design philosophy with its crisp architecture, exposed screws and prominent sapphire crystal. Every element feels purposeful, giving the watch the appearance of a precision scientific instrument rather than a conventional wristwatch.
TIMING MACHINE READOUT
This reading was taken (crown down) with a ONEOF Accuracy Boutique Edition timing machine at time of cataloging. It is provided as a courtesy only, and shall not be construed as a warranty or guarantee of any kind. Please refer to our terms and conditions of sale for more information.
Condition
Watch is in new condition. Papers dated 2026
Our Perspective
Otsuka Lotec has rapidly established itself as one of the most innovative names in independent watchmaking by challenging almost every convention of traditional watch design. The No. 7.5 perfectly captures that spirit, combining ingenious engineering, industrial aesthetics and exceptional rarity into a watch that is unlike anything else on the market today.
Eric Ku
Co-founder
