Ōtsuka Lōtec No. 7.5 “Unworn”

The No. 7.5 by Ōtsuka Lōtec is the brainchild of independent Japanese watchmaker Jiro Katayama, who has cultivated a loyal cult following among connoisseurs of experimental design. While the brand is distributed solely in Japan — purchased via lottery and limited to domestic buyers — it has quietly gained international acclaim for its distinct steampunk aesthetic, novel mechanics, and avant-garde approach to design. Working with a small team, Ōtsuka Lōtec produces less than 200 watches per year.

With its distinctive and unconventional case architecture, the No. 7.5 stands out immediately, defined by a minimalist, industrial aesthetic. Drawing inspiration from 1930s 8mm film cameras, the asymmetrical dial layout — featuring jumping hour, minute, and running seconds displays — offers a compelling visual rhythm. The contrast between straight brushing and sandblasted finishes on the stainless steel case adds depth and texture, reinforcing its utilitarian charm. A sapphire caseback reveals the modified Miyota 82S5 movement, paired with an in-house developed jumping hour module, showcasing a level of craftsmanship rarely seen in watches at this price point.

Released in 2023, the updated No. 7.5 introduced several enhancements over its predecessor. The case material was upgraded from SUS303 to more robust SUS316L steel, while the apertures received a notable upgrade from mineral to sapphire crystal, increasing clarity and scratch resistance. A custom sapphire fisheye lens now magnifies the jumping hour display, and the pin buckle features a newly engraved brand logo, paired with a redesigned leather strap that completes the piece with elevated refinement.