t the beginning of this year, we travelled to Japan to visit Casio’s headquarters in Tokyo and its “mother factory of G-Shock” in Yamagata, in northern Honshu. We published the first part of that report in April, followed by an emotional encounter with Kikuo Ibe, the “Father of G-Shock”.

What we could not reveal at the time was a secret project then nearing completion: the MRG-D5000. According to G-Shock, it is the first MR-G model whose external case architecture is made directly from sapphire crystal while still meeting the shock-resistance standards expected of a G-Shock. This highly exclusive timepiece, limited to just 20 pieces worldwide, is the culmination of seven years of research. It continues the legacy of Ibe’s so-called Dream Project and is perhaps the clearest expression yet of what MR-G has become: a meeting point between uncompromising engineering and Japanese craftsmanship.

The breakthrough

The story of the MRG-D5000 goes back to 2018 and the “Father of G-Shock”, Kikuo Ibe. That year, G-Shock unveiled the G-D5000, an extraordinary interpretation of the original G-Shock design executed in 18-karat gold. The project demonstrated that even a precious metal could be engineered to meet the brand’s requirements for shock-resistance.

At Baselworld that same year, G-Shock presented something even more experimental: a G-Shock concept watch made from sapphire crystal. The material posed a very different challenge. Sapphire is exceptionally hard and highly resistant to scratches, but hardness should not be confused with toughness. Under impact, sapphire can chip or fracture. Creating a construction capable of surviving the punishment expected of a G-Shock therefore proved far more difficult than simply machining a sapphire case. The prototype remained exactly that: a prototype.

After Ibe retired, however, the development team continued working on the idea. The decisive breakthrough came with another project. In 2022, G-Shock introduced the titanium MRG-B5000 with a new Multi-Guard Structure, dividing the bezel and case into numerous separate components rather than relying on a single monolithic construction. According to G-Shock, this architecture uses multiple interacting parts, including shock-absorbing elements, to help protect the case while allowing the complex finishing expected of MR-G. It also opened the door for a renewed exploration of sapphire.

The new development programme was given a suitably poetic name: the Blue Rose Project. Like the once impossible idea of creating a naturally blue rose, a shock-resistant sapphire G-Shock had long seemed beyond reach. The name also echoed the original spirit of the Dream Project: pursuing an idea precisely because it appeared impossible. In 2026, that ambition has finally resulted in a production watch.

A case inspired by Japanese timber construction

The central innovation of the MRG-D5000 is its specially developed Multi-Guard Structure for Sapphire. Rather than machining the outer case from a single block, MR-G divides it into several smaller sapphire components. According to the company, these elements interlock in a structure partly inspired by traditional Japanese timber-frame construction, in which buildings can be assembled through precisely engineered joints rather than nails or screws.

Here, that reference is functional rather than merely aesthetic. Drilling screw holes into sapphire can create potential stress points. Even minute imperfections could increase the risk of cracking. MR-G therefore developed a construction in which the sapphire outer components can be assembled without conventional screw holes, fitting together almost like a three-dimensional puzzle. The solution required entirely new processing and assembly techniques.

The raw material presents another challenge. According to G-Shock, the blue sapphire starts life as large synthetic ingots grown over several months, but not every section offers the same combination of colour saturation and transparency. Only carefully chosen areas can be used for the watch. Once selected, the material still has to be cut and machined into relatively small and complex components. Every additional operation introduces another risk of chipping, cracking or rejection. G-Shock says the result is an unusually slow production process, with only one or two watches completed per month.

G-Shock’s unusual interpretation of luxury

Despite its exotic construction, the MRG-D5000 remains unmistakably connected to the original G-Shock. The familiar square silhouette is preserved, albeit in a slightly enlarged format of around 51.3mm, while the display remains digital, just as it has been since the birth of G-Shock.

That point is more significant than it may first appear. Even at its most expensive and experimental, G-Shock has generally resisted the temptation to imitate the established codes of traditional Swiss luxury watchmaking. The 18-karat-gold Dream Project watch remained digital. The MRG-D5000 is digital too. G-Shock is not trying to disguise the identity of MR-G as it moves upmarket. It is reinforcing it.

Around the display, a stainless-steel element features the signature brick pattern inherited from the earliest G-Shock models. Here, it is finished with a deep blue vapour-deposition coating that echoes the sapphire exterior. The MR-G logo and markings including “SHOCK RESIST” are rendered in pure 24-karat gold, creating a warmer contrast against the intense blue of the case.

The MRG-D5000 also illustrates MR-G’s highly particular vision of luxury. Traditional high-end watches are often treated with caution. Owners may avoid water, impacts or situations likely to mark the case. MR-G takes almost the opposite approach. Its most sophisticated watches are conceived to be worn and used.

The philosophy, as it was explained to us in Japan, is that premium MR-G models should shine outdoors rather than remain protected inside a safe. Their luxury lies partly in this contradiction: sophisticated materials, complex engineering and artisanal finishing are devoted to an object that remains fundamentally functional.

That tension is essential to understanding MR-G, which remains something of a maverick in traditional watchmaking terms. It is not trying to transform itself into a conventional haute horlogerie manufacture. Instead, it is bringing Japanese notions of beauty, precision and utility into an industrial language that belongs entirely to G-Shock. The MRG-D5000 may be visually precious: it is still meant to be worn like a G-Shock.

A laboratory for future G-Shocks

The sapphire outer structure surrounds an internal case made from Grade 5 titanium, protected by a DLC coating. The screw-down caseback also combines Grade 5 titanium with sapphire and carries both the individual limited-edition number, from 1/20 to 20/20, and a reference to the Dream Project. Even the model name points back to its origins: the “D” in MRG-D5000 stands for Dream. The watch is fitted with a specially developed Dura Soft rubber strap, rather than a metal bracelet. Its surface reproduces the G-Shock brick pattern in relief, with the individual blocks set at slightly different angles. As the watch moves, light and shadow shift across the strap, echoing the changing reflections of the sapphire case.

A new titanium clasp has also been developed for MR-G, with particular attention paid to comfort and to the tactile feel of its release mechanism. Even the presentation box extends the concept, combining a vivid blue interior and watch cushion with a transparent rectangular outer shell.

For all the attention devoted to its materials and construction, the MRG-D5000 remains a fully functional digital G-Shock. It offers 20-bar water-resistance, solar power, Multi Band 6 radio-controlled timekeeping, world time, a 1/100-second stopwatch, a countdown timer, five daily alarms and a full-auto LED Super Illuminator.

That functional continuity is important. Sapphire has not been used simply to create a spectacular display object. G-Shock has gone to considerable lengths precisely so that such an unusual material can coexist with the requirements of an MR-G. Beauty does not replace utility. The challenge is that one should strengthen the other.

The broader Blue Rose Project also includes two additional watches incorporating sapphire elements at significantly lower price levels, illustrating how ideas developed at the summit of MR-G can gradually filter through the collection.

This is perhaps the wider significance of the project. The most ambitious MR-G models have increasingly become technological laboratories for G-Shock. Materials, structural solutions and production techniques developed for exceptional pieces can later find their way into more accessible watches.

How far can a G-Shock evolve before it ceases to be a G-Shock? With the MRG-D5000, the answer is surprisingly far. Thirty years after the birth of MR-G, G-Shock is still attempting to make the impossible wearable.