Grand Seiko Evolution 9 "Sunrise" Tentagraph chrono automatic Hi-Beats titanium copper-pink dial titanium bracelet 43,2 mm

The Origins of the Tentagraph

In 2023, Grand Seiko marked a major milestone in its history with the introduction of the Tentagraph, its very first mechanical chronograph. A paradox at first glance, since the brand—rich in more than sixty-five years of expertise—had already produced renowned Spring Drive chronographs celebrated for their smooth operation. But with the Tentagraph, the intention was different: to offer a purely mechanical Hi-Beat chronograph, beating at 36,000 vibrations per hour, capable of standing alongside the world’s best while remaining faithful to the Japanese identity of the brand.

First launched in blue (SLGC001), followed by the ice-toned SLGC007 and the bold Tokyo Lion SLGC009, the Tentagraph quickly established itself as a pillar of the Evolution 9 collection. Its robust silhouette, assertive proportions, and improved ergonomics redefined the role of the sports chronograph within the Grand Seiko universe.

In 2025, the saga expands with a luminous and poetic variation: the SLGC006 Sunrise Tentagraph. Limited to 300 pieces, it draws inspiration from Mt. Iwate, the iconic peak visible from the Shizukuishi Studio. Its copper-pink relief dial pays tribute to the ridges and lava flows of the mountain, here transposed under the golden glow of the rising sun. More than just a chronograph, this creation embodies a vision: that of time experienced in balance between mechanical power and natural beauty.

Mt. Iwate at Sunrise

The case of the Sunrise Tentagraph immediately asserts its character. Crafted from High-Intensity Titanium, a material that is both robust and lightweight, it displays carefully balanced proportions: 43.2 mm in diameter, 15.3 mm in thickness, and 51.5 mm lug-to-lug. Despite this generous profile, its ergonomics—shaped by the Evolution 9 Style—allow it to sit naturally on the wrist, thanks to a lowered center of gravity and lugs that flow seamlessly from the case. The titanium is accented with black ceramic and 18K rose gold details on the crown, pushers, and bezel ring, creating a subtle contrast between restraint and refinement. The alternating satin-brushed and Zaratsu-polished surfaces give it a luminous finish, enhanced by an anti-reflective box-shaped sapphire crystal.

But it is the dial that truly captivates. Its textured motif reflects the rugged surface of Mt. Iwate, whose lava flows and ridges are translated here into a striking relief design. Unlike previous Tentagraph models, this edition offers a deeper, more tactile interpretation, giving a true geological impression. Its copper-pink tone evokes the mountain bathed in the first light of morning, intensified by a subtle gradient that enhances the sense of depth.

The sub-dials also introduce a distinctive palette: burgundy-brown for the chronograph counters, and a darker copper shade for the small seconds. This contrast improves legibility while reinforcing the watch’s unique chromatic identity. The faceted hands and indexes, rose gold-plated and filled with luminescent material, catch the light brilliantly while ensuring optimal readability both day and night. Finally, the date, discreetly positioned between four and five o’clock, preserves the overall balance of the dial without breaking its visual harmony.

The watch is fitted with a matching titanium bracelet, secured by a three-fold push-button clasp, adorned with a rose gold “GS” medallion—a refined detail that completes the harmony of the piece.

The Mechanics of Time in Motion

When Grand Seiko unveiled its very first mechanical chronograph in 2023, the Tentagraph, it was more than a technical achievement: it was a statement of intent. The Caliber 9SC5, which powers today’s Sunrise Tentagraph, reflects this identity even in its name: TEN for its ten beats per second, TA for its three-day power reserve, A for automatic winding, and GRAPH for its chronograph function.

This Hi-Beat movement, operating at 36,000 vibrations per hour, represents the new generation of Grand Seiko. Thanks to its Dual Impulse Escapement and twin barrels, it delivers a 72-hour power reserve, even when the chronograph is engaged—a record among high-frequency chronographs. Its precision is rated at +5/-3 seconds per day in static conditions and between -1 and +8 seconds in daily use.

Yet the 9SC5 is more than just a high-performance engine: it is a blend of innovations designed to offer both durability and fluidity. The chronograph is actuated by a column wheel, ensuring smooth and precise operation of the pushers. The vertical clutch eliminates any jump of the seconds hand at start-up, allowing instantaneous and accurate measurement. Resetting is managed by a three-pointed hammer, which returns the seconds, minutes, and hours hands simultaneously to zero.

Designed and assembled at the Grand Seiko Studio Shizukuishi, the 9SC5 reflects both artisanal expertise and the industrial mastery of the manufacture. Its components, crafted using MEMS technology, optimize lightness and precision, while its free-sprung balance wheel with inertia screws guarantees lasting stability and accuracy. Furthermore, the curved balance design—developed after more than 80,000 simulations—ensures optimal regularity in all positions of the watch.

By combining innovative architecture with refined finishing, the Caliber 9SC5 is far more than a high-frequency chronograph. It embodies Grand Seiko’s ambition: to deliver an exceptional movement that unites energy efficiency, long-term reliability, and poetic mechanical beauty.