uni-ball one P Snoopy PEANUTS Gel Pen - 0.38mm
uni-ball one P Snoopy PEANUTS Gel Pen - 0.38mm
uni-ball one P, shrunk down and dressed in Peanuts artwork
The uni-ball one P is Mitsubishi Pencil's pocket version of the uni-ball one. The "P" stands for pocket: the barrel is short, fat and light, with a round knock and a broad clip, so it sits in a small bag or a pen loop without poking out. This batch pairs it with licensed Peanuts art and a 0.38 mm gel tip in black.
The three designs in this batch
- A — Snoopy & Lucy. Cream barrel with Snoopy and Lucy together, and the line "That's why we love Peanuts" printed along the grip area.
- B — Snoopy & Woodstock. Deep grape barrel, Snoopy and Woodstock, with a white version of the same artwork on the barrel back.
- D — Doghouse. Warm tan-pink barrel built around Snoopy's doghouse, with Charlie Brown's speech bubble "I guess I just don't fit."
The Japanese line has a fourth design, C, built around Charlie Brown in a pale yellow barrel. It is not in this batch.
Specifications
- Tip size 0.38 mm, gel ink in black
- Body 116.8 × 19.2 × 13.9 mm, 13.7 g
- Packaging 190 × 55 × 15 mm, 16 g
- Materials: ABS resin, brass, SUS
- Refill: Mitsubishi Pencil UMR-38S
- Made by Mitsubishi Pencil, Japan; licensed Peanuts artwork
What the 0.38 mm tip is good for
Fine gel lines hold up on small notebook grids, in margin notes and on forms with tight boxes. It is a line width for precision rather than speed: the same gel ink that makes uni-ball one dark and consistent also means a very thin line can feel slightly toothy on rough paper.
Good to know
- Gel ink needs a moment to set. On glossy receipts, sticker paper or coated card, give it a few seconds before you touch the line.
- The 0.38 mm tip is not a good fit for heavy pressure or carbon-copy forms; the point is the point.
- Only the UMR-38S refill fits. Other uni-ball refills have a different tip assembly.
- The barrel is short by design. If you write in a large hand or rest the pen high, a standard-length pen will feel more natural.
uni-ball one P inside the pen range
The one P is filed with uni-ball pens, in gel and rollerball pens and under all pens. If you want a 0.5 mm nib for everyday notes rather than fine lines, the Kutsuwa Cruro stamp pen is the closest match in this Peanuts run, and the SQUARE candy seals cover the paper side.
More in the Snoopy collection
This piece is part of our Snoopy collection, one shelf for every Peanuts item we carry. Readers usually pick it up together with:
- Snoopy Mini Stamp by Kodomo no Kao – a self-inking stamp that needs no ink pad
- Zebra Sarasa Clip 3C Snoopy 2026 – the 3-colour gel pen from the same 2026 Snoopy line
- Kutsuwa Cruro Snoopy Stamp Pen – a rolling stamp built into a pen
- SQUARE Snoopy Candy Sticker Sheet – a sticker sheet for the same planner pages
If you are filling a planner or a notebook page rather than a desk, the same pieces sit in our journaling supplies.
Frequently Asked Questions
Q: What does the P in uni-ball one P mean?
A: Pocket. The uni-ball one P is the short, chunky version of the uni-ball one, designed to drop into a small bag or a pen loop rather than a long barrel case.
Q: Does the uni-ball one P take a refill?
A: Yes, the Mitsubishi Pencil UMR-38S refill. Other uni-ball refills are shaped differently at the tip and will not fit this barrel.
Q: Is a 0.38 mm tip too fine for everyday writing?
A: It suits small handwriting, planner grids and margin notes. If you write large or press hard, a 0.5 mm version of the same pen is the easier choice.
Q: Will the gel ink smudge under a highlighter?
A: Less than a water-based rollerball, but not instantly. Give the line a few seconds to set before running a highlighter over it, and longer on coated or glossy paper.
Q: What is the difference between the Peanuts designs?
A: A has Snoopy and Lucy on a cream barrel, B has Snoopy and Woodstock on a deep grape barrel, and D is built around the doghouse on a warm tan barrel. The pen inside is the same 0.38 mm black gel in all three.