Uni-ball One 3 Review: A Compact Three-Color Pen That Gets the Details Right

Introduction

When Uni announced a three-color pen in the same size class as the Uni-ball One P, it was hard not to get excited. That compact form factor was previously reserved for a single-color ballpoint, and now it holds black, red, and blue gel refills. Released on March 18, 2026, the Uni-ball One 3 launches at 1,980 yen tax included for the gift version reviewed here, with standard versions starting at 1,430 yen. After extended use, the verdict is simple: this is a very well-rounded little pen with only a couple of caveats worth knowing before you buy.

First Impressions and Design

The Uni-ball One 3 is built around a palm-friendly concept: three colors in a body small enough to nearly disappear into your hand. Fitting three refills into this length has its limits, so the barrel is a touch longer than the single-color One P, landing somewhere between the One P and the standard Uni-ball One. That makes it a natural match for small planners and pocket notebooks.

The shape borrows heavily from Uni’s premium Jetstream Prime retractable three-color pen, but with a casual, approachable finish. The resin barrel is light in the hand, the low center of gravity aids control, and the classic Uni-ball One clip is a working, spring-loaded design that grips paper and notebook covers easily. A small metal cone sits at the tip.

Packaging and Gift Version

The pen ships in two lines. Standard models come bare, in two tip sizes and two colors each: 0.38 mm in Glass Green and Sugar Brown, 0.5 mm in Charcoal and Brick Red, at 1,430 yen tax included. The gift version reviewed here adds a paper package with a cut-out window and a hanging string, letting you feel the pen’s texture at the counter. It comes in Lamp White (0.38 mm, with gold clip and center ring) and Record Black (0.5 mm), priced at 1,980 yen.

The gift versions use slightly more refined colorways, and both are part of the regular lineup rather than a limited run, so there is no rush to grab one. Record Black is an all-black pen with a compact, cute-but-cool look, and it fills a gap, since the Uni-ball One P never got a black version.

One honest gripe about the gift packaging: the cut edges of the paper sleeve shed fine dust that clings to the barrel, especially visible on the black finish. Even after a careful wipe-down before use, residue reappears. For a product marketed as gift-ready, that means an extra cleaning step before handing it over, which feels like an oversight Uni could have addressed in the packing process.

One-Handed Rotation That Actually Works

The three-color mechanism is a rotary retract system: turn the barrel until the color marker on the center ring aligns with the end of the clip, and the corresponding tip extends or retracts. The rotation is light and smooth, with a defined stop at each end rather than free spinning, and it is not noisy.

Because the barrel is light resin and this compact size, it rotates easily with one hand, which is genuinely useful when jotting a memo outdoors or on the move. Heavier metal-barrel multi-pens, like the Jetstream Prime, are much harder to operate one-handed. Twisting firmly counterclockwise separates the barrel for refill changes.

Writing Feel and Refill Options

Uni’s signature stabilizer mechanism carries over here, and it matters. Multi-pen refills approach the tip from an angle, so the tip hole must be enlarged, which normally causes the point to wobble or knock around. The stabilizer in the Uni-ball One 3 minimizes that play, keeping the tip steady in a way most budget multi-pens cannot match.

The included refill is the Uni-ball One gel ink (UMRML type), known for crisp, vivid lines that write more boldly than a typical gel. The 0.5 mm sample reviewed here glides smoothly without the scratchiness of a finer point; writers who make dense notes in small planners should consider the 0.38 mm version instead. A nice bonus: Style Fit refills are compatible, so you can swap in other colors and build out the pen to your own needs.

Things to Consider Before Buying

The barrel is fairly thick by modern standards. If you prefer slim pens, this one will not suit your grip, and that is the clearest reason to pass. The packaging dust issue is the other small disappointment, though it affects presentation rather than performance. Neither detracts from what is otherwise a remarkably complete product.

Who Should Buy It

This pen fits three groups particularly well: planner users who want multiple colors in a pocket-sized body, stationery fans who appreciate thoughtful engineering like the stabilizer mechanism, and casual users who just want a pleasant, reliable multi-pen that looks good on a desk. Between the standard and gift versions, there is a color and finish for most tastes, and nothing here is a limited edition you have to chase.

Conclusion

The Uni-ball One 3 hits a genuinely comfortable middle ground: cute enough to feel charming, refined enough to avoid looking cheap, and well engineered where it counts. The steady tip, comfortable grip, one-handed rotation, and compatible refill ecosystem make it easy to recommend to both enthusiasts and everyday writers. If the packaging dust can be forgiven, this is an easy buy, and the Lamp White version deserves a spot on the desk too.