Is This Grand Seiko’s Most Impressive Chronograph Yet?

The Mt. Iwate series continues with a bird’s-eye view at dawn.

Close-up of a watch face featuring a textured rose gold background with three subdials in a darker copper tone. The subdials display 30, 60, and 6 markings. The main dial has rectangular hour markers with white and rose gold accents. A date window shows the number 6, framed in rose gold. The outer bezel is black with white numeric markings ranging from 90 to 180. The watch hands are rose gold with white inlays, and the second hand is black. Small text near the bottom reads "JAPAN 9SC5.

Published September 11, 2025

·

Updated September 11, 2025

If you buy from a link, we may earn a commission. Learn more

Grand Seiko’s Tentagraph is impressive enough with its caliber 9SC5 automatic movement, offering one of the planet’s most accurate mechanical stopwatch complications.

But the Japanese masters of horology elevated it further with a rose gold-imbued revamp inspired by Mt. Iwate at sunrise.

Grand Seiko chronograph watch with a stainless steel bracelet, a textured bronze dial featuring three subdials, gold-tone hands and hour markers, a date window at 4 o'clock, and a black tachymeter bezel. The background shows a softly lit mountain landscape at sunset. — Japan’s Mt. Iwate visually inspires the Tentagraph series.

This is the fourth reference in Grand Seiko’s Evolution 9 chronograph series, which was introduced in 2023 with the SLGC001.

The case and dial fit the aesthetic ideal for auto racing chronographs established by watches like the Rolex Daytona, Zenith Chronomaster Sport and TAG Heuer Autavia.

But the Tentagraph is distinctively a Grand Seiko, inside—thanks to the caliber 9SC5 movement—and out—featuring the brand’s signature intricate dial textures.

Grand Seiko Tentagraph watch with a textured champagne dial featuring rose gold-tone hour markers and hands. It has three subdials in shades of brown and copper, a date window at 4 o'clock, and a black tachymeter bezel with white markings. The watch case and bracelet are stainless steel with rose gold-tone accents on the bezel edge and pushers. — The SLGC006 is the first Tentagraph with precious metal accents.

Following the dark blue SLCG001 and icy blue SLGC007, the newest Tentagraph continues the Mt. Iwate series. This time, the theme is elevated with precious metal accents to strengthen the “golden light of sunrise” aesthetic.

A golden sunrise

Mt. Iwate is the most geologically energetic of Japan’s over 100 active volcanoes. Its sides have been etched with an intricate network of grooves from 700,000 years of recurring lava flow.

a grand seiko watch — The Tentagraph case is made of High-Intensity Titanium.

The dial of the Tentagraph SLGC006 represents the mountains’ scored landscape as seen from above. It has more three-dimensional depth than its predecessors and practically any other dial texture in Grand Seiko’s library.

A copper-salmon hue emulates the first rays of dawn illuminating the mountainside. The theme is heightened by 18-karat rose gold plating on the applied hour markers, minute hand, hour hand and date window frame.

Grand Seiko chronograph watch with a silver stainless steel bracelet and case. The watch face features a textured beige dial with rose gold hour markers and hands, three subdials in shades of brown and copper, a date window at 4 o'clock, and a black tachymeter bezel with white markings. The crown and pushers are rose gold. — This is the first Tentagraph with a differently colored running seconds dial.

Along with the added precious metal, the newest Tentagraph differentiates itself by having a distinct color for the snailed running seconds dial. It is golden copper, compared to the dark burgundy of the snailed 30-minute and 12-hour totalizers.

Rose gold plating on the outer rim of the bezel frame, the pushers and the crown extends the theme to the high-intensity titanium case.

Putting the ten in Tentagraph

Grand Seiko attributes the name Tentagraph to the use of its Hi-Beat 36000 movement, which vibrates 10 times per second. This frequency creates a beautifully smooth sweep for the running seconds and chronograph seconds hands.

Mechanical watch movement with visible gears, screws, and jewels, featuring a winding crown on the left side. The movement is engraved with "GRAND SEIKO TENTAGRAPH" and includes the Grand Seiko lion emblem. The design showcases polished metal components with gold and purple accents. — The Grand Seiko caliber 9SC5 is one of the most accurate mechanical chronograph movements ever made.

The Hi-Beat Chronograph movement also has astounding accuracy. It can measure 1/5 of a second on the chronograph and keep up within +5 and -3 seconds per day. This iteration also packs a 72-hour power reserve when fully wound.

As with most of its watches, Grand Seiko’s impressive automatic chronograph maintained a modest look compared to its Swiss peers. But the new Mt. Iwate ‘Sunrise’ Tentagraph has a luxurious finish matching the prestige of the movement within.

Availability and price

The Grand Seiko Tentagraph SLCG006 ‘Mt. Iwate Sunrise’ will be available from Grand Seiko in October 2025 for $22,600.

Unlike the first two Mt. Iwate Tentagraphs, this is a limited edition reference, with only 300 pieces in production.

Grand Seiko chronograph watch with a stainless steel bracelet and case. The dial features a textured light brown background with three subdials in varying shades of brown and copper. Rose gold accents highlight the hour markers, hands, and pushers. The bezel is black with a tachymeter scale in white. A date window is positioned between 4 and 5 o'clock.

Grand Seiko Tentagraph SLGC006

Specs

Case Size	43mm
Movement	Grand Seiko caliber 9SC5 automatic
Water Resistance	100m

$22,600 at Grand Seiko

About the Author: Brad Lanphear is an associate editor at Gear Patrol covering watches and style. Before joining the publication, he previously wrote for Heddels and Men’s Health. Now, he’s on a never-ending quest to find the perfect pair of Japanese denim.