{"title":"OTSUKA LOTEC","description":"\u003csection class=\"collection-hero\"\u003e\n\u003cp class=\"eyebrow\"\u003eJAPONISTA WATCH ARCHIVE\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cstrong\u003eJapanese Independent Watchmaking with Instrument-Panel Soul\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eMechanical timepieces by Jiro Katayama, where retrograde displays, industrial textures, and small-batch Japanese engineering transform the wristwatch into a wearable machine-object.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003csection class=\"collection-rich-text\"\u003e\n\u003ch3\u003e\u003cstrong\u003eCurator’s Note\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eOtsuka Lotec occupies a rare and thrilling corner of modern horology. It is neither a conventional Swiss luxury house nor a nostalgia-driven heritage revival. Instead, it stands as a distinctly Japanese independent vision shaped by designer and watchmaker Jiro Katayama, whose route into watchmaking began through product design, metalworking curiosity, and the irresistible pull of engineered objects with tactile soul.\u003c\/p\u003e\n\u003cp\u003eWhat makes Otsuka Lotec so magnetic is its refusal to romanticize polish for polish’s sake. These watches do not seek elegance through ornament alone. Their beauty emerges through screws, scales, brushed metal, apertures, discs, retrograde displays, and architecture that feels closer to laboratory instrumentation or dashboard hardware than to salon jewelry. The result is a language of watchmaking that feels tactile, intelligent, and fully authored.\u003c\/p\u003e\n\u003cp\u003eFor collectors, that philosophy matters. Otsuka Lotec is not simply unusual. It is ideologically coherent. The watches are rooted in industrial tactility, mechanical legibility, and the emotional pull of purposeful form. Independent-watch collectors admire the originality. Design collectors respond to the object language. Enthusiasts of Japanese craft appreciate the sincerity of small-scale making and the insistence on personal authorship.\u003c\/p\u003e\n\u003cp\u003eThe current official model family includes No. 8, No. 9, No. 5 KAI, No. 6, and No. 7.5. Rather than overwhelming the market with endless variants, Otsuka Lotec builds a world through numbered forms, each one reading like a distinct mechanical instrument. This makes the collection especially compelling for buyers who value narrative continuity across a maker’s output.\u003c\/p\u003e\n\u003cp\u003eThe No. 6 offers one of the clearest windows into the brand’s thinking: coaxial retrograde hour and minute hands arranged within a fan-shaped display, a central seconds disc, and a date indication, all housed in a case whose architecture feels engineered rather than decorated. It captures the essence of Otsuka Lotec perfectly: design with visible logic, mechanical drama without empty spectacle, and a wrist presence that feels like a machine translated into personal scale.\u003c\/p\u003e\n\u003cp\u003eWithin the broader Japonista universe, Otsuka Lotec belongs naturally among collectible watches, Japanese industrial design, and modern craft objects that blur the line between tool, sculpture, and personal artifact. These pieces do not merely tell time. They stage time as a visible mechanism.\u003c\/p\u003e\n\u003cdiv class=\"concierge-callout\"\u003e\n\u003ch3\u003e\u003cstrong\u003eCollector Concierge\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSearching for Otsuka Lotec references, sold-out numbered models, Japanese domestic-market availability, or collector-grade examples with strong condition? Our \u003ca href=\"https:\/\/japonista.com\/pages\/japan-s-premium-proxy-art-logistics-japonista-concierge-logistics\"\u003econcierge team\u003c\/a\u003e can assist with sourcing-oriented support for serious acquisitions across Japan.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is Otsuka Lotec known for?\u003c\/strong\u003e\u003cbr\u003eJapanese independent mechanical watches with industrial design language, unusual time displays, and highly personal authorship under Jiro Katayama.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWho founded Otsuka Lotec?\u003c\/strong\u003e\u003cbr\u003eThe brand is led by Jiro Katayama, a designer who moved from automotive and product design into watchmaking.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy do collectors care about Otsuka Lotec?\u003c\/strong\u003e\u003cbr\u003eCollectors are drawn to the brand’s instrument-like layouts, small-scale independent identity, and coherent design philosophy rooted in analog machinery, metal construction, and tactile engineering.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat models define the current collection?\u003c\/strong\u003e\u003cbr\u003eThe current official lineup includes No. 8, No. 9, No. 5 KAI, No. 6, and No. 7.5.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003cdiv style=\"display: none;\"\u003eotsuka lotec, otsuka lotec watch, otsuka lotec japan, jiro katayama watchmaker, japanese independent watch, japan independent horology, japanese watch collector, collectible japanese watches, industrial design watches, retrograde watch japan, otsuka lotec no 5 kai, otsuka lotec no 6, otsuka lotec no 7.5, otsuka lotec no 8, otsuka lotec no 9, japanese mechanical watch, artisan watch japan, indie watchmaker japan, instrument dial watch, machine aesthetic watch, small batch watch japan, design-led watchmaking, japanese micro watch brand, miyota 9015 module watch, avant garde time display, engineering inspired watch, analog instrument watch, independent watch collection, luxury japanese watch, niche horology japan, wearable machine object, technical dial watch, collector watch japan, industrial luxury watch, modern japanese design watch, mechanical sculpture watch, rare japanese watch, numbered model watch, independent mechanical watches, japonaise horology, contemporary japanese watchmaking, collectible wrist instruments, design collector watch, precision mechanical watch, japanese workshop watch, modern craft horology, unusual display watch, retrograde complication japan, connoisseur watch selection, curated watch archive\u003c\/div\u003e","products":[{"product_id":"otsuka-lotec-no6-retrograde-watch","title":"Reloj automático Otsuka Lotec n.º 6 con esfera de instrumentos retrógrada, de Jiro Katayama, 40 mm, juego completo sin usar","description":"\u003cdiv class=\"jp-product\" data-world=\"Timepieces \u0026amp; Fine Jewelry\"\u003e\n\u003cp class=\"jp-lede\"\u003eThe No.6 is the watch that placed Jiro Katayama's small Tokyo workshop on the world horological map. Its fan-shaped retrograde scale reads like a laboratory gauge rather than a clock, and this example is new and unused, from the official lottery release of January 2026, with its full set.\u003c\/p\u003e\n\u003ch2\u003eThe Piece\u003c\/h2\u003e\n\u003cp\u003eCreated by Tokyo watchmaker Jiro Katayama, the Otsuka Lotec No.6 is one of the most recognizable designs in modern Japanese independent watchmaking. Instead of hands sweeping over a circular dial, it presents time across a semi-circular measurement arc: the hour and minute indicators travel along fan-shaped retrograde tracks and snap back to their starting point at the end of the scale, mimicking the analog gauges of laboratory equipment, aviation instruments and industrial measuring tools.\u003c\/p\u003e\n\u003cp\u003eA rotating seconds disc adds continuous motion and emphasizes the mechanical nature of the display, and a date display completes the functions. The brushed stainless steel case favors precision finishing over decorative polish, reinforcing an identity closer to instrumentation worn on the wrist than to classical Swiss design.\u003c\/p\u003e\n\u003cp\u003eMechanically, the No.6 follows a modular philosophy: a Miyota automatic movement serves as the base engine, while a proprietary Otsuka Lotec module converts standard timekeeping into the retrograde gauge display. The approach combines proven reliability and a serviceable platform with genuine display innovation, letting engineering effort go into the originality of the display system.\u003c\/p\u003e\n\u003cp\u003eInternational recognition accelerated when the No.6 won the Challenge Watch Prize at the Grand Prix d'Horlogerie de Genève (GPHG), introducing the brand to collectors beyond Japan and giving this reference a particular place in its history. Limited production and distribution make it sought after by independent-watch collectors, mechanical-display enthusiasts, industrial-design collectors and specialists in Japanese horology.\u003c\/p\u003e\n\u003ch2\u003eDetails\u003c\/h2\u003e\n\u003cul class=\"jp-details\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaker:\u003c\/strong\u003e Otsuka Lotec (Jiro Katayama)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e No.6\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLine\/Series:\u003c\/strong\u003e Otsuka Lotec numbered model series (No.5 \/ No.6 \/ No.7.5 \/ No.8 \/ No.9)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrigin:\u003c\/strong\u003e Japan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e 316L stainless steel, industrial brushed finish\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e Case diameter approx. 40 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMovement:\u003c\/strong\u003e Miyota automatic mechanical base with proprietary Otsuka Lotec module; approx. 24 jewels; 21,600 vph; power reserve approx. 40 hours\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunctions:\u003c\/strong\u003e Retrograde hour indicator, retrograde minute indicator, central seconds disc, date display\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrystal:\u003c\/strong\u003e Sapphire with anti-reflective coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCaseback:\u003c\/strong\u003e Exhibition display back\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater Resistance:\u003c\/strong\u003e Daily-use resistant\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrap:\u003c\/strong\u003e Leather\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded:\u003c\/strong\u003e Original box, warranty card, manual, accessories\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Official lottery purchase, January 2026\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCondition\u003c\/h2\u003e\n\u003cp class=\"jp-grade\"\u003e\u003cstrong\u003eJaponista grade S\u003c\/strong\u003e · Unworn or as new, complete with original packaging.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNew and unused, observed in hand.\u003c\/li\u003e\n\u003cli\u003eComplete set with watch, original box, warranty card, manual and accessories.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eOtsuka Lotec Atelier\u003c\/h2\u003e\n\u003cp\u003eOtsuka Lotec was founded in Tokyo by the designer and engineer Jiro Katayama, who came to watchmaking through industrial design, metalworking and a fascination with mechanical instruments rather than a Swiss apprenticeship. His founding idea was that a wristwatch could be treated as a miniature instrument whose architecture, materials and motion communicate time with the clarity of a scientific tool. Brushed plates, exposed screws, engraved scales, retrograde arcs and layered mechanical structures make the dial read like a laboratory gauge, an aviation instrument or a mechanical dashboard.\u003c\/p\u003e\n\u003cp\u003eModels are identified by number rather than name; the No.5 Kai, No.6, No.7.5, No.8 and No.9 trace the evolution of Katayama's design language. Production is small-scale and atelier-like, often distributed in restricted quantities through lotteries or tightly controlled releases within Japan, and the watches typically combine reliable Japanese mechanical base movements with proprietary display modules of Katayama's design.\u003c\/p\u003e\n\u003ch2\u003eAuthenticity \u0026amp; Care\u003c\/h2\u003e\n\u003cp\u003eAcquired new through the official Otsuka Lotec lottery release in January 2026 and accompanied by the maker's warranty card, manual and original box. Every piece is examined and documented in Japan before dispatch and is offered with the Japonista authenticity guarantee.\u003c\/p\u003e\n\u003ch2\u003eDelivery from Japan\u003c\/h2\u003e\n\u003cp\u003ePacked by hand in Japan and shipped insured and tracked by EMS or an equivalent express service. Import duties and taxes, where applicable, are payable on arrival. Returns follow our \u003ca href=\"\/es\/policies\/refund-policy\"\u003epublished policy\u003c\/a\u003e.\u003c\/p\u003e\n\u003cdiv class=\"jp-closing\"\u003e\n\u003cp\u003eConsidered offers are welcome through Send an Offer, and each one is reviewed personally. Pieces over $1,000 may be reserved over several payments with \u003ca href=\"\/es\/pages\/japonista-layaway-privilege-program\"\u003eLayaway Privilege™\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eContinue browsing: \u003ca href=\"\/es\/collections\/collectible-watches\"\u003eCollectible Watches\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"jp-related\"\u003eRelated pieces: \u003ca href=\"\/es\/products\/otsuka-lotec-no-7-5-jumping-hour-automatic-watch-jiro\"\u003eOtsuka Lotec No.7.5 jumping hour watch\u003c\/a\u003e · \u003ca href=\"\/es\/products\/otsuka-lotec-no5-kai-jump-hour-watch-full-set\"\u003eOtsuka Lotec No.5 Kai jump hour watch\u003c\/a\u003e · \u003ca href=\"\/es\/products\/hublot-mdm-skeleton-ref-1512-3-18k-yellow-gold-frederic\"\u003eHublot MDM Skeleton 1512.3 yellow gold watch\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"jp-cta\" data-world=\"Timepieces \u0026amp; Fine Jewelry\"\u003e\n\u003cp class=\"jp-cta-eyebrow\"\u003eReference Hunting\u003c\/p\u003e\n\u003cp\u003eName the reference number, dial and year, and the Hunting Salon™ watches Japan’s collector market for it, then inspects and documents the piece before it ships insured to you. \u003ca href=\"\/es\/pages\/hunting-salon%E2%84%A2\"\u003eRequest a watch search →\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp class=\"jp-search\"\u003eCollectors also search: otsuka lotec no.6 · otsuka lotec no 6 retrograde · jiro katayama watch · japanese independent watchmaker retrograde · otsuka lotec gphg challenge prize · otsuka lotec for sale unused\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Otsuka Lotec","offers":[{"title":"Default Title","offer_id":52072625078565,"sku":null,"price":13750.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0758\/8829\/6229\/files\/OTSUKALOTECNo6RetrogradeWatchJapaneseIndependentHorologyJiroKatayamaInstrumentDial_1.jpg?v=1773383346"},{"product_id":"otsuka-lotec-no-7-5-jumping-hour-automatic-watch-jiro","title":"Reloj automático Otsuka Lotec n.º 7.5 de hora saltante, de Jiro Katayama, indicación mediante disco, 40 mm, juego completo sin usar","description":"\u003cdiv class=\"jp-product\" data-world=\"Timepieces \u0026amp; Fine Jewelry\"\u003e\n\u003cp class=\"jp-lede\"\u003eJiro Katayama's No.7.5 abandons the conventional dial for an instrument panel of three mechanical ports: a jumping hour aperture, a rotating minute disc and a seconds disc magnified by a sapphire fisheye lens. This example is new and unused, with box, documents, strap and tags.\u003c\/p\u003e\n\u003ch2\u003eThe Piece\u003c\/h2\u003e\n\u003cp\u003eDesigned in Tokyo by Jiro Katayama, the Otsuka Lotec No.7.5 is one of the most visually distinctive mechanical watches of Japan's modern independent movement. Time is read through a three-window interface rather than hands: the hour numeral jumps instantly at the start of each hour, a rotating disc replaces the minute hand, and a small seconds disc keeps the dial in constant motion. The arrangement evokes the analog gauges of laboratory equipment and aviation instruments, a miniature mechanical console rather than a classical watch face.\u003c\/p\u003e\n\u003cp\u003eThe seconds display sits beneath a sapphire fisheye lens whose optical distortion adds depth and curiosity. Mechanically the watch pairs the Miyota 82S5 automatic, a durable and serviceable Japanese caliber, with Otsuka Lotec's own jumping hour module, which converts conventional hour and minute motion into the disc-based display while keeping dependable reliability.\u003c\/p\u003e\n\u003cp\u003eThe 316L stainless steel case carries the same industrial philosophy, finished with hairline brushing and sandblasting instead of mirror polish for a utilitarian, tool-instrument appearance. Katayama began building watch cases and mechanical displays in his small workshop around 2008; early prototypes evolved into the numbered system used today, and the brand gained international recognition when the No.6 won the GPHG Challenge Watch Prize.\u003c\/p\u003e\n\u003cp\u003eThe No.7.5 belongs to the modern catalog era, in which Katayama refined modular mechanical displays built on industrial design principles, and it is one of the clearest expressions of that philosophy. Production volumes are extremely limited, which draws independent-watch enthusiasts, mechanical-display collectors, industrial-design enthusiasts and specialists in Japanese horology.\u003c\/p\u003e\n\u003ch2\u003eDetails\u003c\/h2\u003e\n\u003cul class=\"jp-details\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaker:\u003c\/strong\u003e Otsuka Lotec (Jiro Katayama, Tokyo)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e No.7.5\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLine\/Series:\u003c\/strong\u003e Otsuka Lotec numbered model series (No.5 \/ No.6 \/ No.7.5 \/ No.8 \/ No.9)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrigin:\u003c\/strong\u003e Japan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e 316L stainless steel; hairline brushed and sandblasted industrial finish\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e Diameter 40 mm · Thickness 11.2 mm (max 14.8 mm) · Lug width 20 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMovement:\u003c\/strong\u003e Miyota 82S5 automatic base with proprietary Otsuka Lotec jumping hour module; 24 jewels; 21,600 vibrations\/hour; power reserve approx. 40 hours\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunctions:\u003c\/strong\u003e Jumping hour, minute disc, seconds disc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrystal:\u003c\/strong\u003e Sapphire with anti-reflective coating; sapphire fisheye lens for disc magnification\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCaseback:\u003c\/strong\u003e Exhibition sapphire caseback\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater Resistance:\u003c\/strong\u003e Daily-life resistant\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrap:\u003c\/strong\u003e Calf leather\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded:\u003c\/strong\u003e Box, documents, strap and tags\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCondition\u003c\/h2\u003e\n\u003cp class=\"jp-grade\"\u003e\u003cstrong\u003eJaponista grade S\u003c\/strong\u003e · Unworn or as new, complete with original packaging.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eNew and unused condition, observed in hand.\u003c\/li\u003e\n\u003cli\u003eFull set with box, documents, strap and tags.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eOtsuka Lotec Atelier\u003c\/h2\u003e\n\u003cp\u003eOtsuka Lotec was founded in Tokyo by the designer and engineer Jiro Katayama, who came to watchmaking through industrial design, metalworking and a fascination with mechanical instruments rather than a Swiss apprenticeship. His founding idea was that a wristwatch could be treated as a miniature instrument whose architecture, materials and motion communicate time with the clarity of a scientific tool. Brushed plates, exposed screws, engraved scales, retrograde arcs and layered mechanical structures make the dial read like a laboratory gauge, an aviation instrument or a mechanical dashboard.\u003c\/p\u003e\n\u003cp\u003eModels are identified by number rather than name; the No.5 Kai, No.6, No.7.5, No.8 and No.9 trace the evolution of Katayama's design language. Production is small-scale and atelier-like, often distributed in restricted quantities through lotteries or tightly controlled releases within Japan, and the watches typically combine reliable Japanese mechanical base movements with proprietary display modules of Katayama's design.\u003c\/p\u003e\n\u003ch2\u003eAuthenticity \u0026amp; Care\u003c\/h2\u003e\n\u003cp\u003eComplete with the maker's box, documents and tags; base caliber Miyota 82S5 with Otsuka Lotec's proprietary jumping hour module. Every piece is examined and documented in Japan before dispatch and is offered with the Japonista authenticity guarantee.\u003c\/p\u003e\n\u003ch2\u003eDelivery from Japan\u003c\/h2\u003e\n\u003cp\u003ePacked by hand in Japan and shipped insured and tracked by EMS or an equivalent express service. Import duties and taxes, where applicable, are payable on arrival. Returns follow our \u003ca href=\"\/es\/policies\/refund-policy\"\u003epublished policy\u003c\/a\u003e.\u003c\/p\u003e\n\u003cdiv class=\"jp-closing\"\u003e\n\u003cp\u003eConsidered offers are welcome through Send an Offer, and each one is reviewed personally. Pieces over $1,000 may be reserved over several payments with \u003ca href=\"\/es\/pages\/japonista-layaway-privilege-program\"\u003eLayaway Privilege™\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eContinue browsing: \u003ca href=\"\/es\/collections\/collectible-watches\"\u003eCollectible Watches\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"jp-related\"\u003eRelated pieces: \u003ca href=\"\/es\/products\/otsuka-lotec-no6-retrograde-watch\"\u003eOtsuka Lotec No.6 retrograde watch\u003c\/a\u003e · \u003ca href=\"\/es\/products\/otsuka-lotec-no5-kai-jump-hour-watch-full-set\"\u003eOtsuka Lotec No.5 Kai jump hour watch\u003c\/a\u003e · \u003ca href=\"\/es\/products\/lv-tambour-pm-sakura-q1k09-pink-diamond-watch\"\u003eLouis Vuitton Tambour PM Sakura Q1K09 watch\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"jp-cta\" data-world=\"Timepieces \u0026amp; Fine Jewelry\"\u003e\n\u003cp class=\"jp-cta-eyebrow\"\u003eReference Hunting\u003c\/p\u003e\n\u003cp\u003eName the reference number, dial and year, and the Hunting Salon™ watches Japan’s collector market for it, then inspects and documents the piece before it ships insured to you. \u003ca href=\"\/es\/pages\/hunting-salon%E2%84%A2\"\u003eRequest a watch search →\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp class=\"jp-search\"\u003eCollectors also search: otsuka lotec no.7.5 · otsuka lotec jumping hour · jiro katayama no 7.5 · japanese independent jumping hour watch · otsuka lotec miyota 82s5 · otsuka lotec unused full set\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Otsuka Lotec","offers":[{"title":"Default Title","offer_id":52072625701157,"sku":null,"price":10850.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0758\/8829\/6229\/files\/OTSUKALOTECNo7.5JumpingHourWatchJapaneseIndependentHorologyJiroKatayamaDiscDisplayWatch_1.jpg?v=1773382547"},{"product_id":"otsuka-lotec-no5-kai-jump-hour-watch-full-set","title":"Reloj mecánico Otsuka Lotec n.º 5 Kai de hora saltante, de Jiro Katayama, arquitectura revisada, juego completo en estado casi nuevo","description":"\u003cdiv class=\"jp-product\" data-world=\"Timepieces \u0026amp; Fine Jewelry\"\u003e\n\u003cp class=\"jp-lede\"\u003eThe No.5 改 is not simply a revision but a mechanical argument, refined and re-articulated. Where the No.6 leans toward retrograde poetry, the No.5 Kai behaves like a laboratory instrument: a jump hour and rotating minute track rise from layered machinery, and this near-mint example is a full set with a warranty dated 2025\/12\/18.\u003c\/p\u003e\n\u003ch2\u003eThe Piece\u003c\/h2\u003e\n\u003cp\u003eJiro Katayama's No.5 Kai, the revised architecture of the No.5, deliberately dismantles the traditional hierarchy of the dial. A central mechanical bridge sits over layered rotating discs, with peripheral minute indexing and a jumping hour display integrated into the mechanical depth. The layout reads like a pressure gauge, a mechanical counter or an industrial readout: time is no longer hands over a face but data emerging from machinery.\u003c\/p\u003e\n\u003cp\u003eSome collectors pause at the Miyota base, yet Otsuka Lotec's work lies elsewhere. The modified base drives a re-engineered jumping hour system and a central disc architecture that exposes the choreography on the dial side, so the release of energy is visible rather than hidden and reading the time becomes an interaction rather than a glance. It is closer to mechanical interface design than to traditional horology.\u003c\/p\u003e\n\u003cp\u003eThe construction follows the same logic: matte steel surfaces, visible functional screws and emphasized structural geometry, with no decorative polish or Geneva striping. The 316L stainless steel case is finished in a blasted and brushed hybrid, and the sapphire crystal is set to give structural depth to the dial mechanics, placing the watch nearer to aerospace instrumentation and precision measuring devices than to conventional luxury.\u003c\/p\u003e\n\u003cp\u003eWithin Japanese independent watchmaking, where Kurono Tokyo stands for elegance and accessibility, Naoya Hida for classical purity and Hajime Asaoka for haute craftsmanship, Otsuka Lotec occupies its own category as the mechanical experimentalist: structural and conceptual rather than classical, decorative or nostalgic. Releases come in extremely limited batches, and the design is instantly recognizable.\u003c\/p\u003e\n\u003ch2\u003eDetails\u003c\/h2\u003e\n\u003cul class=\"jp-details\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaker:\u003c\/strong\u003e Otsuka Lotec (Jiro Katayama)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e No.5 改 (No.5 Kai, revised architecture)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrigin:\u003c\/strong\u003e Tokyo, Japan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Industrial 316L stainless steel, matte blasted and brushed hybrid finish\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMovement:\u003c\/strong\u003e Modified Miyota base with proprietary jumping hour system\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisplay:\u003c\/strong\u003e Jump hour and rotating minute track (central disc architecture)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrystal:\u003c\/strong\u003e Sapphire\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrap:\u003c\/strong\u003e Black leather; original plus an additional strap\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEdition:\u003c\/strong\u003e Extremely limited batch release\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded:\u003c\/strong\u003e Box, warranty certificate dated 2025\/12\/18, accessories complete\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCondition\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eNear mint, collector grade.\u003c\/li\u003e\n\u003cli\u003eSupplied as a full set with box, dated warranty certificate and complete accessories, including an additional strap.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eOtsuka Lotec Atelier\u003c\/h2\u003e\n\u003cp\u003eOtsuka Lotec was founded in Tokyo by the designer and engineer Jiro Katayama, who came to watchmaking through industrial design, metalworking and a fascination with mechanical instruments rather than a Swiss apprenticeship. His founding idea was that a wristwatch could be treated as a miniature instrument whose architecture, materials and motion communicate time with the clarity of a scientific tool. Brushed plates, exposed screws, engraved scales, retrograde arcs and layered mechanical structures make the dial read like a laboratory gauge, an aviation instrument or a mechanical dashboard.\u003c\/p\u003e\n\u003cp\u003eModels are identified by number rather than name; the No.5 Kai, No.6, No.7.5, No.8 and No.9 trace the evolution of Katayama's design language. Production is small-scale and atelier-like, often distributed in restricted quantities through lotteries or tightly controlled releases within Japan, and the watches typically combine reliable Japanese mechanical base movements with proprietary display modules of Katayama's design.\u003c\/p\u003e\n\u003ch2\u003eAuthenticity \u0026amp; Care\u003c\/h2\u003e\n\u003cp\u003eAccompanied by the Otsuka Lotec warranty certificate dated 2025\/12\/18, original box and complete accessories. Every piece is examined and documented in Japan before dispatch and is offered with the Japonista authenticity guarantee.\u003c\/p\u003e\n\u003ch2\u003eDelivery from Japan\u003c\/h2\u003e\n\u003cp\u003ePacked by hand in Japan and shipped insured and tracked by EMS or an equivalent express service. Import duties and taxes, where applicable, are payable on arrival. Returns follow our \u003ca href=\"\/es\/policies\/refund-policy\"\u003epublished policy\u003c\/a\u003e.\u003c\/p\u003e\n\u003cdiv class=\"jp-closing\"\u003e\n\u003cp\u003eConsidered offers are welcome through Send an Offer, and each one is reviewed personally. Pieces over $1,000 may be reserved over several payments with \u003ca href=\"\/es\/pages\/japonista-layaway-privilege-program\"\u003eLayaway Privilege™\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eContinue browsing: \u003ca href=\"\/es\/collections\/collectible-watches\"\u003eCollectible Watches\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"jp-related\"\u003eRelated pieces: \u003ca href=\"\/es\/products\/otsuka-lotec-no6-retrograde-watch\"\u003eOtsuka Lotec No.6 retrograde watch\u003c\/a\u003e · \u003ca href=\"\/es\/products\/otsuka-lotec-no-7-5-jumping-hour-automatic-watch-jiro\"\u003eOtsuka Lotec No.7.5 jumping hour watch\u003c\/a\u003e · \u003ca href=\"\/es\/products\/audemars-piguet-cobra-18k-yellow-gold-bracelet-watch-twelve\"\u003eAudemars Piguet Cobra yellow gold bead-link bracelet\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"jp-cta\" data-world=\"Timepieces \u0026amp; Fine Jewelry\"\u003e\n\u003cp class=\"jp-cta-eyebrow\"\u003eReference Hunting\u003c\/p\u003e\n\u003cp\u003eName the reference number, dial and year, and the Hunting Salon™ watches Japan’s collector market for it, then inspects and documents the piece before it ships insured to you. \u003ca href=\"\/es\/pages\/hunting-salon%E2%84%A2\"\u003eRequest a watch search →\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp class=\"jp-search\"\u003eCollectors also search: otsuka lotec no.5 kai · otsuka lotec no 5 改 · otsuka lotec jump hour · jiro katayama no.5 · japanese independent jump hour watch · otsuka lotec full set\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Otsuka Lotec","offers":[{"title":"Default Title","offer_id":52174512914725,"sku":null,"price":28980.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0758\/8829\/6229\/files\/OtsukaLotecNo.5KaiJumpHourWatchJapanRareFullSetIndependentJiroKatayama_1.png?v=1775004531"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0758\/8829\/6229\/collections\/otsuka-lotec-mechanical-instrument-cathedral-retrograde-gauge-hero.png?v=1773381108","url":"https:\/\/japonista.com\/es\/collections\/otsuka-lotec.oembed","provider":"Japonista","version":"1.0","type":"link"}