⏱ 5-7 min read
📅 Updated Sep 2026
🔍 1 Watch Reviewed
CHRONOTHEORY&Co is the in-house watch brand of ChronoTheory, a Ginza, Tokyo retailer built around the idea of a "fun watchmaking journey" — right down to a shop interior styled like a futuristic spaceship. The brand's stated mission is to preserve the watch industry's craftsmanship for future generations, and its debut model, the AV-98 ("Advanced Vintage 6498"), is the clearest expression of that yet: a hand-wound dress watch built around the workhorse Unitas/ETA 6498 movement, but finished to a degree that's rare at any price point on this caliber. Here's a full breakdown of the design, movement, materials, and what it costs.
📅 Updated Sep 2026
🔍 1 Watch Reviewed
Quick Verdict
The AV-98 wraps 1930s–1950s dress-watch styling around a modern, single-piece-machined case and a deeply reworked 6498-1 movement, then ships it in a purpose-built leather carrying case instead of a conventional box. Both the case maker (Kyowa Seiko, of MINASE fame) and the dial maker (Shokosha) are established, high-end Japanese specialists, and it shows in the details — recessed, rhodium-plated small-seconds steps, hand-drawn 1940s-style Breguet numerals, chamfered hands down to the seconds hand. It's a genuinely ambitious debut, positioned by the brand as a "smart casual" watch rather than a strictly formal one, though production is deliberately tiny and the price sits well into premium independent territory.
Best for: collectors who want vintage-dress-watch styling with contemporary case-making and unusually deep movement finishing, and who value a watch's manufacturing story as much as the watch itself. Not for: buyers who need something reliably in stock, or anyone shopping strictly by price-to-spec ratio on a 6498-based watch.
Quick Specs
| Case Diameter | 42mm |
|---|---|
| Case Thickness | 9.1mm |
| Lug-to-Lug | 49mm |
| Case Material | Stainless steel, single-piece machined, Zaratsu-polished |
| Crystal | Box-shaped sapphire, double-sided anti-reflective multi-coating |
| Water Resistance | 6 ATM |
| Dial | Brass, lacquer or hairline finish, 0.4mm thick |
| Dial Colorways | Black lacquer / blue lacquer / clear lacquer over bronze hairline |
| Indices & Hands | Brass, yellow-gold plated or rhodium plated |
| Movement | ETA6498-1 CT EDITION |
| Jewels | 17 |
| Power Reserve | 46 hours |
| Frequency | 18,000 vph |
| Winding | Manual |
| Buckle | Stainless steel D-buckle |
| Strap | Alligator (embossed calf leather on export models); 22mm–18mm taper |
| Case/Accessory | Genuine leather carrying case, "WATCHCUBE" |
| Warranty | 3 years (international shipping costs borne by customer) |
| Price | ~$21,000 (¥3,300,000) |
| Production | 3 pieces every 6 months (one of each colorway) |
Brand Story: Why "& Co"
CHRONOTHEORY&Co grew directly out of ChronoTheory's retail floor rather than a traditional atelier. The "& Co" appended to the logotype is meant to signal an intent to "take on the world" alongside a wider network of Japanese engineers and specialists, and the logotype itself was deliberately designed to evoke the branding seen on watch dials from the 1940s — a small detail, but one that sets the tone for a brand built on referencing that era rather than copying it outright.
Design Concept: "Smart Casual," Not Strictly Formal
The exterior was designed by ChronoTheory's Naoto Watanabe, who worked as a graphic designer before turning to watches, and it borrows case structure and detailing from dress watches spanning the 1930s to 1950s. Importantly, the brand doesn't position the AV-98 as a strictly formal dress watch. The stated concept is "smart casual" — proportions and details adjusted so the watch works with everyday casual and business clothing, while still feeling appropriate for a nicer dinner out. That positioning matters for anyone deciding whether this fits their existing collection: it's meant to be worn often, not saved for black-tie occasions.
Case: Machined From a Single Block, No Brazing
The stainless steel case is manufactured by Kyowa Seiko, the company behind MINASE, and it's a genuinely complex piece of machining. The middle case — with its three-dimensional curved sides, expandable lug tops, and flat lug sides — is cut from a single piece of steel rather than welded together, which eliminates any brazing seams. After CNC machining, the case goes through Zaratsu polishing and hand-polishing to achieve a mirror finish while keeping edges sharp and avoiding the wavy distortion that mirror-polished surfaces can pick up.
One specific detail worth calling out: the lug tops sit one level above the top of the middle case, creating a flat, twist-free surface — the effect is that the lug tops at 3 and 9 o'clock line up visually in a straight line, a small but deliberate design choice.
For water resistance, gaskets are placed at every mating surface — between the box-shaped crystal and bezel, bezel and middle case, middle case and screw-back, and screw-back and sapphire display back — which is how the watch reaches a genuinely useful 6 ATM rating despite its antique-inspired case shape. That's enough to shrug off sudden rain or humidity, which the brand specifically frames around everyday use in climates like Japan and Southeast Asia.
Dial: Pocket-Watch-Grade Numeral Work
The dial is made by Shokosha, a manufacturer that produces dials for a number of major Japanese watchmakers' high-end models. It's built from a single piece of brass, with the small-seconds register machined as an integral part of the dial rather than attached separately: the brass base is electroplated and lacquered, the small-seconds area is then machined down to create a recessed step, the exposed brass is rhodium-plated and relacquered, and the top surface is polished — all while keeping total dial thickness to just 0.4mm.
The applied Breguet numerals are around 0.15mm thick, described by the brand as matching the numeral thickness historically used on pocket watches. The typeface itself — used for both the main Breguet numerals and the small-seconds numerals — is an original in-house design referencing 1930s–1940s watches, with the weight and italic angle of individual characters hand-adjusted rather than pulled from a standard font built for double-digit use.
Hands follow the same level of attention: the hour, minute, and small-seconds hands all carry C-chamfered bevels, which read as flat from straight on but pick up a distinctly three-dimensional, pocket-watch-era look from an angle.
Colorways:
- Piano Forte Black — black lacquer mirror-finish dial with yellow-gold-plated indices and hands
- Strato Navy — blue lacquer mirror-finish dial with rhodium-plated (silver-toned) indices and hands
- Timpani Rose — clear lacquer over a bronze-toned hairline-finished dial, with rhodium-plated indices and hands
Movement: ETA6498-1 CT Edition
The base caliber is the widely used, well-regarded ETA 6498-1, running at 18,000 vph. ChronoTheory's version — modified with changes to bridge shaping and the addition of a Triovis-type fine regulator — pushes the finishing considerably further than the base movement typically receives:
The 2nd, 3rd, and 4th wheels of the main going train have chamfered, return-angled spokes
The pallet fork and pallet bridge are broadly chamfered as well, giving the movement a layered, three-dimensional look reminiscent of pocket-watch-era finishing
Operating-system components — crown wheel, ratchet wheel, click wheel, and small setting wheel — are reshaped and polished to the tips of the teeth
The stated goal behind that last point isn't just cosmetic: it's meant to make winding and time-setting feel smooth and tactile, with a clean clicking sensation from the click spring but no perceptible friction or vibration from the gear train while turning the crown — in other words, making the daily ritual of a hand-wound watch something to enjoy rather than tolerate. Independent coverage of the watch has also noted a proprietary semicircular Côtes de Genève decoration and 24K gold plating on the bridges and baseplate, adding to the visual weight of the movement when viewed through the display back.
The WATCHCUBE Carrying Case
Instead of a conventional presentation box, every AV-98 ships in the "WATCHCUBE" — a carrying case designed in-house by ChronoTheory and built from genuine leather inside and out. It's cushioned on all interior surfaces, and the zipper is positioned so it never contacts the watch directly, making it something you could reasonably use to carry the watch day-to-day rather than a box that gets shelved after unboxing.
Price and Availability
The AV-98 is priced at ¥3,300,000. Production is intentionally slow: ChronoTheory plans to build three pieces every six months — one of each colorway — rather than running a single fixed-size limited edition. Warranty coverage is three years, with international shipping costs for service or delivery covered by the customer. Strap material varies by market: alligator leather domestically, with embossed calf leather substituted on export models (a common adjustment for exotic-leather import restrictions abroad).
Given the small, recurring production batches, interested buyers should check ChronoTheory's official site directly for current ordering terms rather than assuming standing inventory.
Pros and Cons
Pros
+ Case machined from a single steel block by Kyowa Seiko, with distortion-free Zaratsu mirror polishing and no brazing seams
+ Dial work — recessed, rhodium-plated small-seconds step, 0.15mm pocket-watch-thickness numerals, hand-adjusted in-house typeface — well beyond typical dial-supplier work
+ Movement finishing (chamfered train wheels, polished operating parts, semicircular Côtes de Genève) rarely seen on a 6498-based caliber
+ "Smart casual" positioning makes it genuinely wearable day to day, not a special-occasion-only piece
+ Transparent sourcing: every manufacturing partner (Kyowa Seiko, Shokosha) is credited by name
+ WATCHCUBE carrying case is a genuinely usable accessory rather than a shelf-bound presentation box
Cons
- 42mm/9.1mm case runs larger than the 1930s–1950s watches it's styled after
- Production is capped at three pieces every six months, making availability the real limiting factor
- No chronometer certification
- At ~$21,000 (¥3,300,000), it's priced well above most other watches built on a 6498 base
Frequently Asked Questions
How much does the CHRONOTHEORY&Co AV-98 cost?
The AV-98 is priced at ~$21,000 (¥3,300,000).
What movement does the AV-98 use?
A modified ETA 6498-1, sold as the "ETA6498-1 CT EDITION." It's manually wound, runs at 18,000 vph, holds 17 jewels, and offers a 46-hour power reserve, with a Triovis fine regulator and extensively chamfered and polished train-wheel and operating-system components.
Is the CHRONOTHEORY&Co AV-98 a limited edition?
Not a fixed limited run — production is ongoing but deliberately slow, with three pieces (one of each colorway) built every six months.
What colorways are available?
Three: Piano Forte Black (black lacquer, yellow-gold indices), Strato Navy (blue lacquer, rhodium indices), and Timpani Rose (bronze hairline dial with clear lacquer, rhodium indices).
What comes in the box?
No traditional presentation box — the AV-98 ships in the WATCHCUBE, a cushioned, genuine-leather carrying case designed in-house by ChronoTheory.
Does the strap differ for international buyers?
Yes. Domestic models use an alligator leather strap; export models substitute embossed calf leather, likely due to exotic-leather import rules in various countries.
Where can I buy the CHRONOTHEORY&Co AV-98?
Directly through ChronoTheory & Co.'s official site (chronotheory.jp), subject to the brand's ongoing small-batch production schedule.
[photo credits: chronotheory.jp]
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