This article provides an early review of the full-metal G-SHOCK "GMW-BZ5000RC-1JR," released in April 2026. This model is the first special edition in the "GMW-BZ5000" series, which was launched in 2025. The special feature is the vibrant, glossy multi-color design. In this article, we will delve into its appeal, including its bold and skillful use of color.
Photographs & Text by Kento Nii
[Article published on January 8, 2026]
The special color for the new G-SHOCK is "Rainbow"!
In 2025, Casio unveiled the "GMW-BZ5000" as a new series of full-metal G-SHOCK watches. Its biggest selling point was its new shock-resistant structure and design, which were developed by training a generating AI with years of research data. Casio had actively utilized AI technology in concept models and the "MTG-B4000" series, but this cutting-edge approach was also adopted for the full-metal G-SHOCK.
The series has received a great response in the market since its debut, and of the three initial releases, the silver-colored model proved so popular that it sold out shortly after its release on the official online shop.
One of the contributing factors is that, while incorporating the aforementioned new design, it also possesses a classic face reminiscent of the original G-SHOCK "DW-5000C." As a new addition to the full-metal G-SHOCK series, which has garnered strong support as a "slightly better" G-SHOCK, this series has gotten off to a very strong start.
The GMW-BZ5000 series, including this model, is only available for purchase at the official online shop and CASIO WATCH Partner Shops. Features include Tough Solar technology, approximately 22 months of operation on a full charge (with power saving mode), a stainless steel case (49.3mm x 43.6mm, 13mm thick), and 20 ATM water resistance. Price: 121,000 yen (tax included).
This time, I had the opportunity to review the "GMW-BZ5000RC-1JR," a new addition to the GMW-BZ5000 series. As it's touted as the series' first special piece, it's clear that it's attracting a lot of attention. Let's take a closer look at its appeal below.
Clever color scheme that takes advantage of the new structure
The highlight of this model is undoubtedly the special rainbow color scheme. And the way it's incorporated is truly bold. Not only are multi-colored square lines drawn around the LCD using glass vapor deposition, but the entire center case is also coated with IP coating, giving the side view of the case back half a glossy rainbow finish.
In contrast, the bezel and bracelet, which make up the face half of the case, exude a solid, metallic feel, with meticulous polishing and a brushed finish. The inverted LCD display means that black occupies a large portion of the face, giving it an almost austere impression.
In this model, the combination of these two elements is truly unique. From the front, it doesn't look all that different from a silver full-metal G-SHOCK. However, in the side view, where the new structure is visible, the colors that were previously subdued suddenly shine brightly, and the two-tone effect with the silver case really stands out.
Furthermore, upon closer inspection of the front view, several differences from conventional full-metal G-SHOCK watches can be observed.
For example, the lugs extending from the center case to the bracelet peek out from the G-SHOCK's characteristic indentations that protect the buttons from impact, with orange visible at the top of the watch and blue at the bottom. The screws, finished in a muted gold color, add a subtle accent to the face. Someone who sees this watch without knowing its specifications might initially perceive it as a silver, full-metal G-SHOCK, but the glimpses of vibrant colors will gradually reveal the strong individuality hidden within.
G-SHOCK has frequently used rainbow colors in its past models, whether made of resin or stainless steel. Designs that incorporate rainbow colors throughout the entire watch are not uncommon, and this seems to reflect the broad appeal that is characteristic of G-SHOCK, which exploded in popularity in the street fashion scene. However, in this model, by utilizing its unique design and deliberately incorporating the striking multi-colors in a more understated way, it creates a look that is both eye-catching and easy to match with various outfits.
While I wouldn't actively wear it on my wrist in business settings, it was a fun watch that made me want to show off its side to everyone around me in my private life.
The case is a new design, but it feels comfortable to wear.
This is my first time actually holding a watch from this series, so I wanted to check how it felt to wear. The case size of this model is 49.3mm in height, 43.6mm in width, and 13mm in thickness. Compared to the conventional full-metal G-SHOCK "GMW-B5000" series, the height and thickness remain the same, while the width has increased by about 0.4mm. I thought I might be able to feel this difference when actually wearing it, but there wasn't a noticeable difference.
The bracelet also appears unchanged from previous models, and the feel when worn remains the same. The shape, with its closely spaced links, fits comfortably on the wrist without any discomfort. The bracelet accommodates wrist sizes up to 20.5cm, and for me, removing 7 links was just right. Incidentally, since it is connected with spring bars, adjustment is possible with just a thin pin. In addition, the buckle can be finely adjusted in four stages, allowing for a perfect fit.
The watch itself weighs 172g, which is about 6g heavier than the "GMW-B5000" series. However, the fact that the size and weight remain almost unchanged despite such a drastic design change is perhaps even more surprising. The lower center case is more sturdily built, and the center of gravity is likely located towards the bottom of the watch. There was no feeling of it swinging around on the wrist.
It's also feature-rich. You can even switch to a classic font.
Needless to say, its practicality is impeccable. In addition to shock resistance, it boasts 20 ATM water resistance. While it's a watch in a price range that might make you hesitant to actually wear it in active situations and test its performance, this toughness is reassuring in the event of an accident.
In addition to Tough Solar power, it features MULTIBAND6 radio wave reception, which supports Japan, North America, Europe, and China. It also includes standard functions such as world time, stopwatch, and alarm. Furthermore, by using Bluetooth and the dedicated "CASIO WATCHES" app, it can be linked with a smartphone to enable detailed settings, automatic time correction, and even phone finder.
All of this information is displayed on an MIP (Memory-in-Pixel) LCD. This is a display capable of fine detail, also used in G-SHOCK's professional line, and the information can be clearly read even in bright sunlight.
Furthermore, it displays a large amount of information at once, and by combining it with the sub-window in the upper right corner when viewed from the front of the face, you can freely combine and display the year, date, day of the week, dual time, triple time, and more. It can be said that this G-SHOCK has received steady upgrades not only in its exterior but also in its system.
Summary
This article reviews the latest full-metal G-SHOCK, the "GMW-BZ5000RC-1JR." Rainbow colors are not a feature offered by many brands, but Casio, with its extensive experience in watchmaking, has managed to create a timepiece that truly showcases the fascinating interplay of colors.
Furthermore, even setting aside the color scheme, the newly designed case is superb. Traditional full-metal G-SHOCKs were constructed from a single piece, from the bezel to the case sides, through precise forging. However, in this model, the clear division between the upper and lower parts of the case results in a greater amount of visible external detail, enhancing the overall mechanical feel. For gadget enthusiasts like myself, this is an irresistible feature.
The only regrettable thing is that, judging from the fact that it's called a special model, it seems this is likely a limited-edition piece. Up until now, G-SHOCK watches that prominently feature multi-color designs have often been positioned as limited editions, as the color schemes themselves are not for everyone.
However, while this work features rainbow colors as its main theme, it achieves a very delicate balance in its expression, not literally overemphasizing them. "With this balance, I'm sure many people will want to try out these unique colors." It was such a well-made product that I felt that way. I conclude this review by taking my hat off to the discerning eye and judgment of those who have already arranged to purchase it so soon after its release.
