Orient Star has announced a new M45 F7 Mechanical Moon Phase watch with a mother-of-pearl dial featuring brown gradation.
Limited to 180 pieces, this timepiece belongs to Orient Star’s new M45 watch collection inspired by the star cluster Pleiades, also known as “Subaru” in Japan.
In 2021, Orient Star released a Mechanical Moon Phase watch (Reference RK-AY0108S) to mark the brand’s 70th anniversary. Limited to 200 pieces, it featured a simple moon phase design omitting the openwork at 9 o’clock while inheriting classical design codes such as Roman numerals, railway track scale and leaf-shaped hands.
In 2022, the brand launched a limited-edition (reference RE-AY0116A) with a mother-or-pearl gradated dial inspired by the moon reflected on Lake Tazawa in Akita Prefecture.
The newly released Mechanical Moon Phase watch (reference RE-AY0121A) is based on the same theme, poetically symbolising Lake Tazawa at night as winter approaches.

The brown dial, created by combining mother-of-pearl and gradation that blackens towards the circumference, evokes the surface of the lake at night, while the silvery moon on the moon phase disc represents the moon floating behind the clouds.
The distinctive expression woven by the mother-of-pearl is individually unique, evocative of the gentle moonlight illuminating the reflections of the lake as the clock ticks quietly by, and late autumn breeze blowing across the water.
The elaborate details, such as the three-dimensional printed Roman numerals, a black ring separating the dial, and the transparent concealed Orient Star “OS mark” printing on the dial, can also be seen clearly through the dual-curved sapphire crystal with anti-reflective coating on both sides.
In addition, the bronze colour plated bezel set in a high-quality stainless steel (SUS316L) case connects the dial and Cordovan leather strap in a continual tone of brown, creating a sense of elegance and luxury.
An exchangeable metal bracelet is included with a butterfly deployant buckle with pushbuttons and half-length links to fine tune the size for optimum comfort.

Powering this watch is the automatic mechanical in-house calibre F7M65, which offers a power reserve of 50 hours as well as stable high accuracy of +15 seconds to -5 seconds per day.
Finally, the beautifully finished movement can be admired through the sapphire crystal see-through case back.
Technical details
Model: Orient Star M45 F7 Mechanical Moon Phase with Mother-of-Pearl Gradation Dial, Reference RE-AY0121A
Movement
Automatic (with hand winding) mechanical in-house calibre F7M65
Accuracy: +15 seconds ~ -5 seconds per day
Moon phase function (moon phase adjusting device attached)
Power reserve indicator
Second hand hacking
22 jewels
Date
Power reserve: 50 hours
Case
Stainless steel (SUS316L, bronze colour plated bezel and crown)
Lug to lug: 49.0 mm
Width: 41.0 mm
Thickness: 13.8 mm
Front glass: Dual curve sapphire crystal SAR (super anti-reflective) coating
See-through exhibition case back with limited edition and serial number engraving
Water resistance to 5 bar (50 m)
Dial
Mother-of-pearl (brown gradation)
Strap
Cordovan leather (brown) / trifold deployant buckle with push button / width 20 mm / exchangeable metal bracelet
Edition
Limited edition of 180 pieces
Other versions
Reference RK-AY0120A: With brown crocodile strap and additional steel bracelet, limited edition of 350 pieces