On the case back, it says 「勤続30年」 – thirty years of service. Above it, embossed in the center, is the Igeta emblem: a diamond-shaped well frame with the character 三 inside it. The symbol of the Mitsui Group.
This watch was not purchased in November 1974; it was presented. Someone had worked at Mitsui for thirty years, and the company expressed its gratitude in the way that was customary in Japan at the time: with a fine watch, engraved and ceremoniously presented.
Counting back, the recipient joined in 1944. That is a remarkable professional life. He began at Mitsui when it was still one of the four major zaibatsu – those family conglomerates that dominated the Japanese economy until the end of the war. He witnessed the American occupation administration dismantle these corporations starting in 1946, saw how the successor companies regrouped in the 1950s, and saw the birth of the Mitsui keiretsu. And he was still there when Japan had become the world's second-largest economy in 1974.
A symbol from the year 1673
The Igeta emblem is one of the oldest continuously used trademarks in Japan. It traces back to Echigoya, which Mitsui Takatoshi opened as a dry goods store in Edo in 1673 – with a revolutionary idea for the time: fixed prices, cash payments, no haggling, and selling even small quantities. Echigoya later became the Mitsukoshi department store, and the trading house became the Mitsui conglomerate.
The sign itself combines two elements: 井桁, the square wooden frame of a well, and the character 三 for "three" inside it – together a rebus for the name 三井, "three wells." Thus, this case back bears an emblem that was already three hundred years old at the time of the engraving.
For collectors, commemorative watches of this kind are a category of their own. They were built exclusively for the Japanese domestic market, they carry a verifiable date and provenance, and they were generally treated with care. Anyone collecting JDM watches looks specifically for engravings of this nature – and one with the Mitsui symbol belongs to the pieces that are rarely seen on the market.
The Lord Matic within the Seiko hierarchy
The Lord Matic (LM) series was introduced in 1968 and occupied the upscale middle segment for Seiko: above the Seiko 5, and below the King Seiko and Grand Seiko. It was manufactured at the Suwa factory – the facility that developed the Grand Seiko in parallel, while Daini was responsible for the King Seiko. This internal competition between Suwa and Daini was the driving force that brought Japanese watchmaking of the 1960s and 1970s to a world-class level.
Technically, the Lord Matic benefited directly from this. The caliber 5606 belongs to the 56 movement family – the same architecture upon which the King Seiko caliber 5626 and the Grand Seiko caliber 5646 are built. The Lord Matic ran at a lower frequency and had simpler fine-tuning than its more expensive siblings, but the basic construction is the same. This is why the 5606s are still considered exceptionally robust and watchmaker-friendly today.
That Mitsui chose a Lord Matic for a thirty-year service award fits the picture: not a prestige watch meant for showing off, but a technically serious timepiece that could be worn daily.
The Caliber 5606A
- Automatic with auxiliary hand-winding – unlike older Seiko automatic movements, the 5606 can also be wound by hand
- Hacking seconds when pulling out the crown, allowing for precision time setting
- 23 jewels
- Quickset for day and date
- Bilingual day wheel, Japanese and English
The bilingual version can be seen in the photo: the day of the week is shown as 土 – Saturday – in blue. Seiko color-coded the Sunday in red and the Saturday in blue on their Japanese day wheels, in accordance with the Japanese calendar. A small detail not found on European watches.
The Dial
The true showpiece of this watch is the dial: a rich green that transitions from a bright, almost turquoise center to a dark bottle green toward the edges. These gradient dials – known in collector jargon as dégradé or fumé – were a huge trend in the mid-1970s, and Seiko implemented them particularly consistently in the Lord Matic.
The effect lives through the light. In the shade, the dial looks almost black; under direct light, the bright center opens up and the green glows. It is complemented by applied, faceted baton indices and slender polished hands that provide contrast. The dial is labeled SEIKO, AUTOMATIC, the LM emblem, and "23 JEWELS," with the Suwa factory symbol beneath.
The calendar window at three o'clock is framed by an applied bezel and displays the day and date side-by-side.
Condition
Technically flawless. The watch was professionally serviced by a watchmaker in Japan in the spring/summer of 2026 – completely disassembled, cleaned, oiled, and regulated. The automatic winding, manual winding, hacking feature, and quickset for day and date function perfectly.
To be honest: The dial shows a number of small dark spots, distributed across the surface, most noticeable in the upper area and around the hand axis. They are clearly visible in the detailed photos; when worn and viewed from a normal distance, they recede behind the color effect. This is a common aging symptom for gradient dials of these years – the dark peripheral zones are lacquered and are more sensitive than classic sunburst dials.
The stainless steel case shows age-appropriate signs of wear; the bezel has a few fine scratches, but the case edges are well-preserved. The crystal has slight signs of use. The case back shows the usual opening marks alongside the engraving; the engraving and stamps are complete and clearly legible.
It is mounted on a black leather strap with crocodile embossing and light stitching.
Technical Specifications
- Brand / Line: Seiko, Lord Matic (LM)
- Reference: 5606-8050
- Serial Number: 4N7287
- Production Date: November 1974
- Movement: Seiko Caliber 5606A, automatic with hand-winding, 23 jewels, hacking seconds
- Manufacturer: Suwa Seikosha, Japan
- Functions: Hours, minutes, central seconds, quickset date and day, bilingual day wheel (Japanese/English)
- Case: Stainless steel, case back engraved with 「勤続30年」 and the Mitsui Group Igeta emblem
- Diameter (without crown): 36.7 mm
- Height: 9.5 mm
- Lug-to-Lug: 41.8 mm
- Lug width: 18 mm
- Weight (incl. strap): 49 g
- Strap: black leather strap with crocodile embossing
- Crystal: Acrylic glass
- Service: Spring/Summer 2026, Japan – complete disassembly, cleaning, oiling, regulation
For whom
For collectors who collect Japanese watches not only for the technology but for what they stood for – the engraving makes this watch a dated document of Japanese labor culture. For lovers of 1970s gradient dials, which are rare outside of Japan and particularly rare in green. And for anyone looking for a technically high-quality automatic movement with hand-winding, hacking seconds, and quickset without paying the premium for a King Seiko.
For those who appreciate tangible Japanese economic history, this piece offers documentation, not decoration: a trademark from 1673 on a watch from 1974, presented for thirty years of service.
With a diameter of 36.7 mm and a height of 9.5 mm, it is flat and discreet enough to slip under a shirt cuff.
Warranty (used)
This is a used item. The statute of limitations for defect claims (statutory warranty) is 12 months from delivery.
Note
As this is a vintage watch, water resistance cannot be guaranteed. To protect the movement, the watch should not come into contact with water or moisture.
