Compiled from 5 sources; we haven't tested this product ourselves yet. How we research
Quick answer
The uni-ball One 3 (UME3-SR) is Mitsubishi Pencil's first 3-color uni-ball One pen: black, red and blue pigment gel ink, selected by twisting a short, thick body. It launched in Japan on March 18, 2026 at ¥1,430 (about US$9.10), in 0.38 and 0.5 mm. JetPens lists it at 129 mm and 15 g.
On this page11 sections
The uni-ball One 3 in Brick Red, 129 mm long (drawn at 1 mm = 5 px).
Plastic body, metal wire clip; water-based pigment gel ink
Released
March 2026*
Price range
$$$5–20 per pen (multi-packs divided by the count)
Colors
Grass Green0.38 mm
Ink colors
black
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Notes on these facts
Made by Mitsubishi Pencil Co., Ltd.. Country of manufacture not stated: Mitsubishi Pencil's Japanese product page and press release, JetPens and the Amazon.com listing we read on October 22, 2026 don't state a country of manufacture. Price: example listing. Released: Japanese launch date in Mitsubishi Pencil's press release of March 6, 2026.
Colors: names per Mitsubishi Pencil Japan, checked October 24, 2026. Body colors and ball sizes per Mitsubishi Pencil's Japanese UME3-SR page; the boxed gift version (UME3-SRG) per its gift page (names romanized from its katakana; Grass Green as JetPens spells it). Every body holds black, red and blue pigment gel ink. Tints were sampled from Mitsubishi Pencil's product photos; ink tints from its single-color uni-ball One photos. Tints are representative, not measured. Shops stock different colors.
Price bands are typical US retail, checked October 2026. Conversions to US dollars are approximate, at October 2026 rates (US$1 = ¥158 = ₩1,330 = NT$32.5 = CN¥6.7 = SEK 9.9 = DKK 6.7 = ₺49.6 = C$1.41 = A$1.43 = CZK 21.7; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).
Key takeaways
Mitsubishi Pencil launched the uni-ball One 3 in Japan on March 18, 2026, at ¥1,430 (about US$9.10) with tax.
It is the first 3-color pen in the uni-ball One series, with the line's dark pigment gel ink in black, red and blue.
JetPens lists it at 12.9 cm (5.1 in) long and 15 g; an Amazon.com listing gives 129.1 × 18.9 × 13.9 mm with the clip.
Refills are the UMR-ML-38S or UMR-ML-05S, listed at ¥165 (about US$1.00) each in Japan.
A gift version in Lamp White or Record Black costs ¥1,980 (about US$13) and comes boxed.
What is the uni-ball One 3?
It is the first 3-color pen in Mitsubishi Pencil’s uni-ball One series: black, red and blue pigment gel ink in a short, thick twist body. It went on sale in Japan on March 18, 2026, at ¥1,430 (about US$9.10) with tax.
The single-color uni-ball One is known for ink that stays on top of the paper, so black looks darker and colors brighter. The One 3 keeps that ink and the open wire clip, and adds a rotating mechanism that Mitsubishi Pencil says suits planners and work bags.
uni-ball One 3 specs
Spec
Value
Maker
Mitsubishi Pencil Co., Ltd., Japan
Model
UME3-SR-38 / UME3-SR-05
Mechanism
Twist (rotating)
Inks
Pigment gel, black, red and blue
Ball
0.38 or 0.5 mm
Length
12.9 cm (5.1 in), JetPens
Diameter
13.7 mm at the grip, JetPens; 13.9 mm body, Amazon listing
Weight
15 g, JetPens
Refill
UMR-ML-38S / UMR-ML-05S
Japanese list price
¥1,430 (about US$9.10)
Mitsubishi Pencil doesn’t publish a length or weight on the pages we read, so sizes come from JetPens and an Amazon.com listing.
Why is the One 3 so short?
Mitsubishi Pencil designed it as a short, thick body with a “stabilizer” that sets the balance point, so it is easy to carry yet steady to write with. JetPens notes the barrel is wide, like the single-color One P.
The One 3 is 10 mm shorter but much thicker than the single-color One.
That makes it a pen for a planner loop or a small pouch rather than a shirt pocket. For a longer, heavier metal twist pen with a single ballpoint refill, see the uni Jetstream Prime Twist.
What colors and versions are there?
Four regular body colors and two boxed gift versions. Grass Green and Sugar Brown come in 0.38 mm, Shirt Blue and Brick Red in 0.5 mm, each with a colored ring as an accent.
The gift version costs ¥1,980 (about US$13). Lamp White (0.38 mm) has champagne-gold painted clip, ring and tip, and Record Black (0.5 mm) has black and gunmetal parts.
What refills does the One 3 take?
The UMR-ML multi-pen refill, in 0.38 mm (UMR-ML-38S) or 0.5 mm (UMR-ML-05S), at ¥165 (about US$1.00) each in Japan. Mitsubishi Pencil lists the same refill for both the regular and gift versions, so any black, red or blue One multi-pen refill fits.
JetPens sells the 0.5 mm refills singly in black, blue and red as uni-ball One Gel Multi Pen Refills. The pen ships with black, red and blue installed; the ink is pigment-based gel, which JetPens describes as fast drying and bleed resistant.
The gift version is a little heavier: the Amazon.com listing gives 18.4 g for the Record Black, against JetPens’ 15 g for the regular Brick Red.
How does it compare with other 3-color pens?
It is a gel-ink pen for color-coding notes; for erasable ink, the Pilot FriXion Synergy 3 is the 2025 equivalent. That pen uses a 0.4 mm Synergy Tip, weighs 13 g and lists at ¥1,100 (about US$7). The water-based uni-ball ZENTO 3-color is Mitsubishi Pencil’s other new 3-color line. Our best gel pens covers single-color options.
Can you buy the uni-ball One 3 in the US?
Yes: JetPens lists all six colors, and Japan-import sellers list it on Amazon.com. On October 22, 2026, the Amazon.com gift-version listing showed 126 ratings and “50+ bought in past month,” and JetPens’ Brick Red page had 6 reviews. US prices put it in our $$ band ($5–20).
Where is the uni-ball One 3 made?
Mitsubishi Pencil doesn’t state it on the pages we read, and the US listings don’t either. We list it as not stated until we can check a package.
Frequently asked questions
How do you change colors on the uni-ball One 3?
Twist the barrel. A colored ring shows which of the black, red or blue refills is out.
What refills fit the uni-ball One 3?
Mitsubishi Pencil lists the UMR-ML-38S (0.38 mm) and UMR-ML-05S (0.5 mm), ¥165 (about US$1.00) each in Japan. JetPens sells them as uni-ball One Gel Multi Pen Refills.
Do standard uni-ball One refills fit the One 3?
Not that we can confirm. The One 3 uses the UMR-ML multi-pen refill, while the single-color One uses UMR-05S style refills, so buy the ML type.
What is the uni-ball One 3 gift version?
A boxed version in Lamp White (0.38 mm) with champagne-gold painted parts or Record Black (0.5 mm) with black and gunmetal parts, at ¥1,980 (about US$13).
What body colors does the uni-ball One 3 come in?
Grass Green and Sugar Brown in 0.38 mm, Shirt Blue and Brick Red in 0.5 mm, plus the two gift colors.
Is the uni-ball One 3 sold in the US?
Yes, as an import. JetPens lists all six colors, and Japan-based sellers list it on Amazon.com.
