Hands-On: Rado True Square x Ji Chang-wook Review

A Collaboration Built on Curiosity

There’s a certain honesty in collaborations that begin by accident. Not the kind born around a boardroom table, but the kind that start when someone asks just the right question at just the right moment. According to brand literature, that’s essentially how the Rado True Square Open Heart x Ji Chang-wook came to be, and after spending time with the watch, that story feels embedded in its design.

Ji Chang-wook

For those unfamiliar with Ji Chang-wook, he’s a South Korean actor whose career has travelled comfortably between action, romance, comedy, and drama—often within the same year. He first came to wide attention through a run of television roles in the early 2010s and has since built an international following thanks to series such as Healer, K2, Suspicious Partner, and Backstreet Rookie, along with a growing slate of film appearances. What sets him apart isn’t simply his versatility, but the easy warmth and approachability he brings to his work—qualities that translate naturally into his role as Rado’s global ambassador, and into the collaborative spirit behind this new True Square edition.

A Visit That Became a Project

When Ji Chang-wook joined Rado as a global ambassador in 2023, the plan was simple: show him around the brand’s high-tech ceramic facility, answer a few questions, and send him back with a deeper understanding of the “Masters of Materials” philosophy. What actually happened was a bit different.

According to the team, Ji didn’t simply tour the facility—he tagged along mentally, following every step of ceramic formulation, casting, and finishing. He asked about colouring techniques, the behaviour of raw ceramic powders, how sapphire crystal is grown, and why certain processes are handled the way they are. It wasn’t small talk; it was the genuine curiosity of someone who likes knowing “how things work” before he’s meant to have an opinion on them.

Somewhere between the ceramic ovens and the sapphire crystal discussion, an idea formed: why not create a watch together?

And once the seed was planted, it took on its own momentum. The square monobloc case of the True Square came up, as did bracelet options, and the idea that a watch inspired by an open, warm personality ought to let a little more light through. That set the team thinking about an open-heart design, which in turn led to sapphire on the back, and then Ji suggested adding rubies.

Not for extravagance. For good luck.

Then Ji told the team, which included CEO Adrian Bosshard, “The ruby also happens to be my native birthstone. Full disclosure. Now you know.”

^{Hour markers are inset with rubies @calibre321}

A Watch Shaped by Conversation

The matt black high-tech ceramic case has the familiar monobloc smoothness that Rado has quietly perfected over the years. It’s lightweight and warm to the touch, giving it a more tactile personality than its geometric silhouette might suggest. This model measures 38 mm across and wears almost like a slim framed picture on the wrist—flat enough to feel modern, but not so severe as to feel cold.

^{A slender picture frame at your wrist @calibre321}

The open heart aperture keeps the dial from slipping into minimalism. Instead, it gives the watch a small window into its own mechanics, revealing the R734 calibre’s balance wheel and decoration. The circular-grain finishing and Côtes de Genève bridges sit recessed beneath vertical brushing, creating a bit of depth without drifting into drama.

And, of course, the rubies. Twelve, in fact—full-cut stones arranged in place of hour markers. Seen in person, they’re not flashy. They serve more as small, warm punctuation marks against the black vertically brushed dial. Their shape and colour read clearly, but they don’t pull the eye away from the open heart or the quiet geometry of the case.

The moment this one entered my studio, my wife said, “Now that’s a beautiful watch!”

On the Wrist: Familiar, but Personalised

If you’ve worn a True Square before, the sensation is familiar. The watch hugs the wrist cleanly, helped by the integrated ceramic bracelet and its titanium folding clasp. The 9.7 mm thickness keeps the watch calm and low-slung. The high-tech ceramic does a good job to keep fingerprints at bay, and the smoked sapphire caseback contributes a soft, muted glow instead of a stark exhibition window.

The open heart is the most expressive element, but even here the watch stays grounded. It feels like a personal touch, not a performance. Red Super-LumiNova on the hands adds a subtle nod to the ruby markers—not flashy, just in the same family of thought.

What I found most striking wasn’t a single feature but the overall mood: a geometric ceramic watch with enough openness to avoid austerity and enough personality to feel like a collaboration rather than an endorsement. The limited run of 987 pieces suits that spirit—just enough to mark the moment, not enough to turn it into a spectacle.

Specs

Case	High Tech Plasma Ceramic 38 Diameter 44.2mm Lug to Lug 9.7mm Thick /w Glass 20mm Lug Width Display Case Back 50m Water Resistance
Dial & Crystal	Sapphire Crystal /w AR Black, vertically brushed with nickel bevels 12 ruby index (.560 carat) Rhodium-coloured anchor White, printed minute track Baton handset Super-LumiNova
Movement	R734 Nivachron Hairspring 21 600bph 25 Jewels 80-Hour Power Reserve
Strap	3-Link High Tech Plasma Ceramic /w Butterfly Clasp

Rado True Square Open Heart x Ji Chang-wook

^{Red markers for good luck @calibre321}

Final Thoughts

The result of this collaboration isn’t loud, and it doesn’t try to reinvent what Rado already does well. Instead, it shows how a small set of conversations can influence the feel of a watch—a different dial texture here, a set of rubies there, an openness inspired by a personality.

It’s a calm, thoughtfully assembled ceramic timepiece that captures a moment in Rado’s relationship with Ji Chang-wook, without straying from the brand’s longstanding design language.

And in the end, that balanced approach might be what makes the watch feel most authentic: it’s unmistakably a True Square, but with a few notes that only make sense if you know the story.

Pricing & Availability

The Rado True Square Open Heart x Ji Chang-wook retails for $5000 CAD. As an added feature, customers that order via Rado’s recently launched Canadian online boutique will receive their True Square Open Heart in a box signed by Ji Chang-wook (while quantities last).

^{Rado True Square Open Heart x Ji Chang-wook @calibre321}

About the author

Brent Robillard is a writer, educator, craftsman, and watch enthusiast. He is the author of four novels. You can follow him on Instagram.

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