Within the world of vintage watches, Grand Seiko – like this full-serviced 1964 Grand Seiko 43999 (57GS) "Kyosan Seisakusho Electric" Chronometer dress watch here – with its distinctive "Grammar of Design," inhabits the top of the food chain, simple as that.  Put simply, the Grand Seiko 43999 embodies the early “grand” ideals set forth by Seiko.
 
Grand Seiko watches were the most painstakingly designed and exquisite watches made by Seiko, produced by both the Dani and Suwa factories.  Introduced in 1963, the GS 43999 was the first Grand Seiko with a date complication (a significant advancement for Grand Seiko at the time), equipped with Seiko’s proprietary fast-forward mechanism. 
 
Why do we call this sharp Grand Seiko 43999, "Kyosan Seisakusho Electric?"
 
Kyosan Seisakusho Electric ((京三製作所, or KSE / Kyosan Electric Manufacturing Co.,Ltd.) was founded by Tokio Kobayakawa in 1917 in Tokyo, and the company manufactures and sells electrical equipment – first for medical applications and foundational electromechanical equipment, and then railway signal management and safety equipment as Japan modernized.  The Japan-based company produced numerous technological firsts for Japan and the world – KSE even made one of Japan’s first automobiles in 1931, the Kyosan-go.  
 
KSE would manufacture Japan’s first electrical relays, first railway automatic signaling and crossing alarm devices, and a slew of other world-first railway safety devices from the early years up through the computer age.
 
KSE’s product areas – historically and in the contemporary age – include railway signaling solutions, traffic management solutions, power conversion solutions, safeguards for passenger transfer areas, and passenger information display systems.
 
Starting in 1995, KSE began manufacturing semiconductors, showcasing its ability to increasingly manufacture high tech railway management solutions, while at the same time also low-tech solutions (like the world’s first railway/metro “gap filler” between the train car and platform).
 
In 2024, KSE had a capitalization of 6.27 billion yen ($42.2 million) and employed 2,054 throughout the globe, with most in Japan but also offices in U.S., China, and Europe.  In the company’s “Medium-Term Management Plan 2025,” asserting its plan to secure KSE’s future growth via expansion of its railway signaling systems and power electronics businesses
 
As mentioned, KSE – under its Kyosan Automobile Company subsidiary – successfully tested and began producing a prototype half-ton truck, its Kyosan-go.  Powered by a single cylinder 500cc engine, it was soon replaced by a two-cylinder 750cc powered three-quarter ton truck.  Of note, Nissan didn’t commercialize its first passenger car and Toyota didn’t make its first prototype vehicle until 1935.  But KSE already had experience in the auto industry – it had been manufacturing auto parts for other companies since 1928, in particular Japan Ford Automobile (yes, that Ford).
 
At its height in the late 1930’s, KSE was producing 150 Kyosan-go trucks a month – and one of its trucks was the only vehicle to successfully summit Mt. Fiji in 1937, beating out multiple other auto companies.  However, World War II would put a halt on KSE’s auto aspirations, with materiel becoming increasingly scarce – production was ended in 1938 after 2,020 trucks had been produced.
 
Seiko introduced the chronometer-standard 43999 as a successor to its inaugural Grand Seiko, the J14070, and it laid the groundwork for Taro Tanaka's influential "Grammar of Design" through its pioneering case architecture and the introduction of Zaratsu polishing techniques.
 
Speaking of Grand Seiko design, in the early 1960s, Seiko’s Tanaka created a set of design principles he called The Grammar of Design.  In 1962, Tanaka noticed Swiss watches "sparkled brilliantly" and realized the design of high-end Seiko watches could be radically improved through the implementation of "flat and conical surfaces perfectly smooth and free of distortion."
 
Tanaka’s Grammar of Design made the Grand and King Seiko lines instantly recognizable as status symbols in the hierarchical Japanese business world of the 1960s and 1970s.  Tanaka’s rules would go on to fundamentally change Seiko’s design language.  All surfaces and angles of the case, dial, indices and hands had to be flat and geometrically perfect to best reflect light.
 
Following this aesthetic, bezels were to be simple two-dimensional faceted curves.  And third, no visual distortion from any angle was allowed, and all cases and dials had to be mirror-finished.  In “A Journey in Time: The Remarkable Story of Seiko,” Tanaka’s approach to the new style is described as follows:

“He started by creating cases and dials that had a perfectly flat surface, with two-dimensional curves on the bezel as a secondary feature.  Three-dimensional curves were not used, as a general rule.  He also decided that all distortion should be eliminated from the dial, too, so that it could be finished with a mirror surface.  This formed the basis for the new Seiko style.”
 
For a brief period in the late 1960’s and early 1970’s, some Seiko’s were certified chronometers by Bureaux officiels de contrôle de la marche des montres (precursor to COSC).  Seiko's history with the Swiss official chronometer rating is an interesting one, from Seiko's first participation in 1963 to its entry of the 45 calibre in 1968.
 
Seiko nearly always placed rather well vis-a-vis its Swiss competition - almost certainly to the embarrassment of the Swiss.  When the successor to the chronometer contest was established, the COSC standard, the Swiss made the odd decision that "all parts used to build the movement must be made within Europe” ... jealous much?
 
Make no mistake, Grand Seiko then and now marks the very best Seiko has to offer, easily on par with the vast majority of what Switzerland has to offer by way of competition.  And the Grand Seiko 43999 SD represents one of the highest achievements of Grand Seiko – namely, creating one of the best watches on the planet.  Period.
 
This Grand Seiko 43999 comes on a premium leather strap, and with a nylon strap, rugged travel case, and springbar tool.