Written by: Jin Fujisaki / Published: 2026-02-23
Have you ever walked into a stationery shop, scanned the pen aisle, and had your eye caught by a uniquely "short and plump" pen that stood out from all the rest? That pen is Mitsubishi Pencil's "uni-ball one P." The "P" at the end of its name stands for Pocket. True to its name, its rounded, short body slips perfectly into a small sacoche bag, a shirt's chest pocket, or a planner's pen holder.
But this isn't just a mini pen made by simply shortening the length. The barrel's thickness is exquisitely designed so that when you pick it up, it settles naturally between your fingers. People with smaller hands will love it, of course, but even adult men can grip it without feeling cramped — it achieves an almost magical sense of hold. Its greatest charm is its mascot-like cuteness, which can soothe you just by sitting and rolling around on your desk.
| A Genuine, "Low-Center-of-Gravity" Writing Feel That Defies Its Looks
image Hands
The assumption that "a short pen equals a simple pen for jotting memos" crumbles the moment its tip touches paper. The uni-ball one P's tip is built with an internal metal "stabilizer mechanism" (a metal weight), designed to push the pen's center of gravity dramatically downward (toward the tip).
Thanks to this low-center-of-gravity design, you won't experience that "too light and wobbly" feeling typical of short plastic-barrel pens. The pen's own weight transfers directly onto the paper, so you can draw steady, unwavering lines without applying unnecessary pressure. Beneath its adorable appearance lies a serious, almost stoic dedication to "the act of writing" — a hidden capability that makes it a genuine, professional-grade writing instrument.
| The Bold, Rich "One Ink" That Sticks in Your Memory
image Mitsubishi Pencil
The ink it uses is the series' signature "uni-ball one ink." Through a newly developed pigment, the ink is prevented from soaking too deeply into the paper's fibers, allowing the colorant to stay on the paper's surface at its true, intended density.
As a result, compared to typical gel ink ballpoint pens, "the blacks come out blacker, and the colors come out more vivid." Joint research between Mitsubishi Pencil and a university has even demonstrated that this "bold, rich text" helps cement information in memory when you read back over your notes. With a smooth writing feel and fast-drying performance that resists smudging, it works stress-free across every scene — from fine entries in your planner to rough sketches when brainstorming ideas.
| Sweet, Gentle Barrel Colors Inspired by Fruits and Sweets
image Mitsubishi Pencil
Another element that cemented this pen's popularity is its color lineup. It comes in soft, gentle, muted shades inspired by fruits and sweets, with names like "Mikan (Mandarin)," "Momo (Peach)," "Hakka (Mint)," "Coffee," and "Yogurt."
The pink-gold accent on the clip (on some models) adds a refined touch, giving it the polished presence of a "lifestyle goods" or "cosmetic" item rather than a piece of stationery. Limited colors such as "Rose Gold" have recently joined the lineup as well, allowing you to "choose by barrel color" to match your smartphone case, planner cover, or favorite nail polish — a fashion-item style of enjoyment that's uniquely modern.
| In Summary: A Companion You'll Want to Carry Everywhere, for Just 550 Yen
image Mitsubishi Pencil
The price is 550 yen including tax (excluding certain limited-edition models). It's a step up from the standard ballpoints in the 100-yen range, but considering its excellent writing feel powered by metal parts and its overwhelmingly satisfying design, it's actually almost too cheap.
The "Mitsubishi Pencil uni-ball one P" is a little spice in everyday life — something that lifts your mood just a bit every time you use it. When you need to jot a quick memo on the go, pulling this plump little pen out of your bag is sure to bring a smile to your face at its sheer loveliness.
