Whether it's sunglasses, denim, kitchen knives, socks or any of a wide range of products, a "Made in Japan" label today generally means a premium quality product. The country is known for craftsmanship, expensive tastes, attention to detail and strict quality standards, and these also apply to watches. Though once overlooked and under-appreciated, Japanese watches and the movements inside that power them now enjoy deserved respect.
Despite all the love for Japanese watches, however, the companies often have confusing strategies and messaging — and watch movements are a perfect example.
From Seiko's vast range of watches to Citizen's quartz Eco Drive and its Miyota subsidiary's mechanical movements found in all manner of third-party watch brands, there's a lot to take in. Understanding Japanese watch movements is, at least, a lot narrower a topic than Swiss watch movements — because there are primarily only a couple companies making watch movements in Japan that are particularly important to understand: Seiko and Citizen. (We also love Casio and Orient, which you can learn more about here.)
Each of these companies, however, is more like a Swiss conglomerate in size, complexity and the scope of their products. We can't possibly treat every Japanese movement in a manageable article (we don't want to murder you with boredom) and there are exceptions to almost every generalization about Japanese brands and movements — but a brisk breakdown of the most common or important examples will help you get a better grasp of the Japanese watch movement landscape.
Seiko Watch Movements
Seiko is a watchmaking behemoth that competes toe-to-toe with the Swiss. Its movements include simple but robust automatics found in its entry- and mid-level watches, the higher-end movements in Grand Seiko watches and even haute horology in its Credor brand. In addition to the specific Seiko movement families covered below, the following proprietary technologies are part of what characterize many Seiko movements, and they're found across a range of Seiko movements:
Diashock: Diashock is something like the Incabloc found in many Swiss watch movements. It's a bearing that protects sensitive components from shock, and you can often see it through watches' display casebacks at the center of the oscillating balance wheel.
MEMS: Micro Electro Mechanical Systems (MEMS) originated in the semiconductor industry and is a technology that allows for precision production of components with tolerances of one micron.
Spron: Spron is Seiko's own metal alloy developed for watch movements' springs but has since even been adopted for use in other industries. According to Seiko, its properties are "superior elasticity, great strength and high heat and corrosion resistances."
Magic Lever: Seiko's grandiosely named Magic Lever is part of the system in an automatic watch that allows the rotor's movement to wind the mainspring. It allows for efficient winding when the rotor rotates in either direction and alongside many comparable solutions in Swiss movements, it requires fewer parts and lends to the robustness of the movement.
Seiko 7S Series Movements
The 7S series of automatic movements are older and seem to be being phased out of current production Seiko watches. They are, however, worth knowing about because they're still found in watches available online like the old Seiko 5 and popular SKX series, and they're the basis of more modern Seiko movements.
Although basic and industrially produced, they're impressively robust for their prices. Notably, they don't offer the ability to wind the movement manually (relying instead on automatic winding only) nor the ability to stop the seconds hand (hacking) when setting.
Seiko 4R (or NH) Series Movements
The 4R series of movements are Seiko's upgrade of the old 7S (above) which are found in modern Seiko watches at the entry level and slightly above. Compared to the 7S, they offer hand winding and hacking (though not the earlier 4R15 and 4R16), and they're often treated to better finishing. As newer movements, they can also be expected to benefit from more modern production. These are generally affordable and functionally basic movements, so it was particularly notable when Seiko added a GMT version to its lineup.
The 4R series is used in Seiko-branded watches while the same movements are sold to third parties with names starting with NH (e.g., 4R36 = NH36). The 7S movements were also sold as NH, the 7S25 being the same as NH25, for example.
Seiko 6R (or NE) Series Movements
The 6R family is similar to the 4R, but it's upgraded and found in Seiko's more premium watches closer to the $1,000 mark and above. It also features hacking and hand winding as well as longer power reserves (often around 70 hours), but its accuracy tolerances are also tightened compared to the 4R. (A note: Unlike the Swiss, Seiko's accuracy claims err on the side of caution, and most users find the movements outperform the promised precision.) When sold to third-party watchmakers, the 6R family is branded as NE, though other premium movements like the 8R chronographs are also sold as NE.
Grand Seiko Movements
Grand Seiko is branded and marketed as a separate company, and indeed the watches tend to stand above their counterparts in the likes of the dressy Presage and sporty Prospex lines branded only as "Seiko." Here, you can expect a higher level of movement and watch on par with Swiss luxury brands. Generally speaking, Grand Seiko movements begin with the number nine, and the type of movement is indicated by the following letter: S for mechanical, R for Spring Drive and F for quartz. You won't see them used by third-party brands, but some Grand Seiko movements will find their way into Seiko watches under different names with perhaps different (lesser) finishing.
Grand Seiko 9S Series Mechanical Movements
The 9S series is where you'll find all of Grand Seiko's traditional mechanical watch movements. They include hand-wound and automatics, as well as more special examples like GMTs and "high-beat" watches that operate at a higher rate of 5Hz. You'll find all of Seiko's premium technology and materials here, as well as refined and over-engineered mechanisms with shimmeringly beautiful finishing.
Grand Seiko 9R Series Spring Drive Movements
Seiko's Spring Drive technology is like nothing else in the watch industry, and it's probably the only example of a movement that can genuinely be considered "hybrid" technology. It's hybrid in the sense that it's powered (driven) by a spring-like traditional mechanical watches but regulated by a quartz crystal instead of an oscillating balance wheel.
Beyond just being impressively innovative and interesting, Spring Drive watches are as accurate as quartz (very) but offer some of the same connection to traditional watchmaking as mechanical watches — and their seconds hands have an even smoother sweep. Many Spring Drive watches have offered an aesthetically polarizing power reserve display on their dials, but this has recently begun to change.
Grand Seiko 9F Series Quartz Movements
The first quartz watch came from Seiko in 1969. While watches using 9F family movements are often less expensive than other Grand Seiko watches, we're talking about high-end quartz — and you'll find these movements are not only hyper accurate, but beautifully decorated just like other Grand Seiko movements. The motion of the hands is more refined (no wobble), and you'll overall find that if you want the accuracy and reliability of quartz timekeeping, this is some of the best you can get.
Citizen Watch Movements
Citizen presents an odd case when it comes to watch movements: while they own one of the biggest manufacturers of mechanical movements in the world, Miyota, they're rarely used in their own watches. This has changed slightly in recent years, but Citizen watches still focus primarily on Eco-Drive quartz movements with solar charging. It's also worth noting that Citizen owns Swiss movement maker La Joux-Perret, but here we're only talking about Japanese movements.
Miyota 8000 Series Movements
These movements are roughly comparable to Seiko's entry-level offerings: the newer versions are like the Seiko 4R series featuring hacking, whereas the older versions are more like the Seiko 7S which doesn't. Since the names are the same, you'll want to look closely at the movements features or just ask when buying a watch with, say, the common Miyota 8215. Though not pretty nor exceptionally accurate, these are the movements you'll find in some of the most affordable automatic watches you'd actually want to buy.
Miyota 9000 Series Movements
As compared to the 8000 series, which Miyota considers "Standard Automatic," the 9000 series is the company's "Premium Automatic" movement family. And they really are solid, on par with many common automatic Swiss movements — or the Seiko 6R series, in some respects (though not the long power reserve). These are the movements you'll find in many of the microbrand watches offering the very best bang for the buck.
