2023 marks the 40th anniversary of Casio’s beloved G-Shock line, and as we pass into the second half of a year packed with celebrations the Japanese giant shows no signs of slowing down its cavalcade of commemorative releases. The upscale MT-G sub-line is the latest collection to celebrate four decades of G-Shock, bringing together an array of material firsts for the series into one of the visually wildest and most capable models ever to wear the MT-G nameplate. Although its audacious rainbow ion-plated color palette may not be for the faint of heart, the new Casio G-Shock MTGB3000PRB1 “Aurora Oval” takes the “statement watch” side of G-Shock to vivid and dynamic new frontiers while preserving the ruggedness and capability that has made the line a fan favorite for four decades.

Although the 50.9mm-wide, 12.1mm-thick stainless steel and carbon case of the Casio G-Shock MTGB3000PRB1 “Aurora Oval” shares its form and dimensions with previous versions of the MTGB3000 series, Casio takes this familiar shape in a radically different visual and material direction. Of course, the immediate focal point is the vibrant, variegated rainbow ion plating on the main case body. Intended to evoke the colors of the Aurora Borealis as seen from space, this ion plating smoothly transitions between a spectrum of golds, greens, blues, pinks, and purples that wind chaotically around this case’s aggressive mix of sharp planes, angles, and projections. While it may be inspired by the Northern Lights, on the wrist this wild, eye-catching finish calls to mind everything from heat-stained exhaust pipes to Mardi Gras beads, with a presence that absolutely demands attention. The chunky, angular bezel takes this look to another level with a series of unique material treatments. For the first time in an MT-G model, Casio uses both recrystallization and deep-layer hardening on this bezel, creating a distinctive flecked, matte finish beneath the rainbow of hues. These treatments are not just for show, however, and Casio claims these processes lead to a substantially harder and more scratch-resistant material than untreated stainless steel. The brand contrasts this spectrum of colors with copper ion plating for each of the four broad, low pushers, along with deep purple ion plating on the crown and the central segments of the integrated lugs.

Casio continues to play with its use of color around the solid caseback, which cuts through its rainbow ion plating in selected raised areas to create highlights of radially brushed stainless steel. The fundamental process behind creating the effect might be simple, but the final effect packs a serious visual punch, making an intriguing highlight out of a region many watchmakers choose to neglect. Despite the 50.9mm diameter, psychedelic colors, and experimental finishes, the G-Shock MTGB3000PRB1 is surprisingly balanced on the wrist. Much of this wearability comes from Casio’s well-documented prowess in ergonomics — the MTGB3000 series case has always wrapped itself around smaller wrists effectively, and the design hides much of its bulk through clever case geometry. Over the past few years, however, Casio has made slimming down its case profiles a priority, particularly throughout the MT-G family. This model comes in at a full 1.1mm-thinner than several of its MTGB3000 stablemates from 2022, and this more focused, restrained cross-section makes an outsize impact on perceived bulk on the wrist. For context, this 12.1mm-thick case is substantially slimmer than most mechanical chronographs on the current market, and reasonably slim for even a three-hand automatic dive watch. This is a major departure from the immensely thick G-Shocks of years past and helps to impart a more upscale feel to the MT-G family. As one might expect, this case is immensely durable as well, with 200 meters of water resistance and the brand’s Carbon Core Guard internal structure for added shock resistance.

When compared to the audacious rainbow-plated case, the dial of the Casio G-Shock MTGB3000PRB1 “Aurora Oval” is far more straightforward and familiar. The radially brushed black main dial surface provides a simple foundation for the design, while the MTGB3000 series’ asymmetric subdials at 3 o’clock, 6 o’clock, 7 o’clock, and 9 o’clock are rendered in an aggressive, legible red-on-black color palette. The outer seconds track printed on the high-sloping rehaut echoes this vibrant red hue, as does the 4:30 date window, while the lume plots atop the applied indices add a splash of cornflower blue to the equation. This blue tone also appears as a highlight for select dial text throughout the design, adding a sense of visual cohesion here. Casio also keeps the line’s standard broad, tapering sword handset intact, rendered here in brushed steel and medium gray. The brand’s decision to keep the dial relatively pared-back when contrasted with the chromatic spectacle of the case is likely a wise one, but it does tie in that multicolored aesthetic through the applied MT-G emblem at 12 o’clock. This emblem is given a fully iridescent treatment, appearing as either silver or a myriad of colors depending on lighting conditions and the viewing angle. It’s difficult to call anything about the MTGB3000PRB1 subtle, but this small touch does add a sense of thoughtful continuity to the design as a whole.

Like the rest of the MTGB3000 series, Casio powers the G-Shock MTGB3000PRB1 “Aurora Oval” with its in-house Module 5672 quartz movement. As with most modern G-Shock powerplants, the Module 5672 offers a truly staggering array of complications, including a 24-hour chronograph, a world timer, a 24-hour countdown timer, LED dial illumination, a perpetual calendar accurate to the year 2099, radio-controlled automatic time calibration, an automatic power saving mode in low-light environments, Bluetooth connectivity, and mobile device pairing through the Casio Watches app. While the radio-controlled time calibration feature means the Module 5672 is more or less perfectly accurate in the vast majority of situations, the movement offers an accuracy of +15/-15 seconds per month without signal reception and a power reserve of up to 18 months after a full solar charge. To complete the package, Casio pairs the watch with a suitably audacious integrated strap in translucent purple rubber. The slightly ghostly quality of this deep purple strap lends even more visual drama to the overall design, while a copper ion-plated keeper ties in visually to the case and bears the commemorative G-Shock 40th anniversary four-star logo.

The 40th anniversary of the G-Shock line has already seen some truly wild and boundary-breaking designs from Casio, but the new Casio G-Shock MTGB3000PRB1 “Aurora Oval” may well be the boldest visual statement of the bunch. The new Casio G-Shock MTGB3000PRB1 “Aurora Oval” is available now for pre-order through the brand’s e-commerce platform. MSRP for this watch stands at $1,400 USD as of press time. For more information, please visit the brand’s website.