Ōtsuka Lōtec

Jiro Katayama began with a small lathe, not a watchmaking apprenticeship. He had worked in automotive design and later designed products including helmets and household equipment. Around 2008, he bought a bench lathe through an online auction and began learning to machine metal.

The maker's biography describes the lathe standing in his kitchen. A car was beyond its scale; a watch case was not. Katayama studied machining and watchmaking while continuing his design work, and began selling watches in 2012.

That route into watchmaking helps explain the appearance of Ōtsuka Lōtec. Screws, plates and moving displays are conspicuous. The watches resemble small pieces of equipment, but the equipment does not always do the same thing. One design separates hours and minutes, another sends hands across arcs, and another uses numbered discs.

The differences matter more than a sequence of model numbers. The No. 6 won the Challenge Watch Prize at the 2024 Grand Prix d'Horlogerie de Genève. The No. 5 KAI, introduced the following year, has a different satellite-hour display. It is not the prize-winning watch under another name.

Katayama also works with specialist suppliers. A purchased automatic movement can power a display designed in his workshop, and miniature bearings can come from a company that makes them for many other industries.