The new Grand Seiko Moonlit Birch SLGW007

Last year, for Watches & Wonders 2024, Grand Seiko introduced a rather important new model – well, a pair of models, to be precise, with the Birch Bark SLGW003 and SLGW002. A new member in the Evolution 9 family, it was the first to be categorised as thin and elegant, but also came with something quite special on the back… Grand Seiko’s first hand-wound hi-beat movement in 50 years, the in-house and handsome Calibre 9SA4, itself based on the automatic and innovative Calibre 9SA5. This year, this appealing watch comes back in a new edition, the Moonlit Birch SLGW007, with a steel case, a navy blue dial and a more casual strap. 

The Evolution 9 collection and specifically the Birch series of models has been quite a ride for Grand Seiko, gathering great success with the Hi-Beat SLGH005 and Spring Drive SLGA009, followed by variations in black or green. Last year saw the introduction of a much thinner, more compact and more elegant variation around this theme, the Birch Bark SLGW003 and its rather impressive hand-wound movement. Now, the brand presents a new edition of this characterful dress watch, which couldn’t be more GS and Japanese, yet dressed in blue, to reflect the “quiet scenery of white birch trees in the moonlight.”

Just like the Birch Bark Titanium SLGW003 and 18k rose gold SLGW002, the new Moonlit Birch SLGW007 is housed in a case that adopts all the traits of the Evolution 9 family, yet has adapted them to a more formal environment. The case is identical in shape and dimensions to the 2024 editions, meaning 38.6mm in diameter and 45mm in length, with a thickness just under 10mm – which isn’t something you’ll see often in a Grand Seiko watch. The case uses the classic sharp facets and combination of brushed and Zaratsu-polished accents that the brand is known for, but everything has been refined and toned down for more elegance.

The bezel is in the same vibe as the White Birch and its derivatives, but has been slimmed down to offer a larger dial opening. And importantly, this new SLGW007 is now made of stainless steel. Considering the fact that the watch is fairly compact and slim, I do think that steel is more appropriate in this context to give it more weight and presence on the wrist – the titanium edition almost felt too light to my taste. In any case, it remains a lovely watch to wear, with refinement and yet a certain audacity.

As for the dial, if the texture is entirely the same as the Birch Bark Titanium SLGW003, the new navy blue colour is said to be “an ode to the moonlight scene of Iwate’s birch trees,” near the birthplace of mechanical Grand Seiko timepieces and the Hiraniwa Plateau with its large forest of white birch trees extending. These trees have inspired Grand Seiko for several watches, and here, the intricate and irregular pattern clads itself in navy blue, “expressing the beauty of white birch trees appearing faintly in the moonlight.” What remains unchanged are the hands and markers, which follow the principles of the case: Evolution 9 design language, but in a slimmer, more elegant version. All elements of the dial are here silver-toned.

Under the sapphire caseback is the handsome and technically advanced in-house calibre 9SA4. Developed on the basis of the automatic 9SA5 found in many recent Grand Seiko watches, it still incorporates the brand’s innovative Dual Impulse Escapement beating at a high frequency of 5Hz (36,000 vibrations/hour) as well as its twin-barrel architecture guaranteeing a solid 80-hour power reserve. Its accuracy is rated at -3/+5 seconds per day. The back reveals a beautifully designed engine, with a transversal bridge holding the balance and hairspring in place, a barrel click in the shape of a wagtail bird, and a refined decoration with thin stripes, elegant finish of the ratchet wheel, and bevelled bridges. Finally, in order to retain the dial’s clean and symmetrical design, the power reserve indicator is positioned on the back.

Finally, the Moonlit Birch SLGW007 comes with a new textured cowhide strap. I know it’s a bit of a detail, but I’m pleased to see something less formal and old-school than a black crocodile leather strap. These too-classic straps have long been one of my main complaints with GS watches, so this new, more casual blue strap is a welcome update.

Released as part of the permanent collection, the Grand Seiko Evolution 9 Moonlit Birch Hi-Beat 36000 80 Hours SLGW007 will be available from Grand Seiko Boutiques and select retailers worldwide as of October 2025. It will be priced at EUR 10,200 (compared to EUR 12,000 for the SLGW003 titanium edition). For more details, please visit grand-seiko.com.