Mitsubishi Pencil UMNSP38.52 Gel Ballpoint Pen Uni-Ball One P 0.38 Huka

0.38 pen is great for my Hobonichi Techo Weeks; thin writing is ultra fine and clear. Works well on Tamoe paper: smooth and dries relatively fast (no blotting or blowing dry as with fountain pens). Standard black ink is not streaky but is very clear. The chubby barrel relieves my hard grip as I write, and I find I can write a bit longer than with a thinner barreled pen. Soda is a nice color and helps determine ink colors I keep (red black blue). I use it daily for Techo, notes to mom, and sermon notes. Never thought a Japanese pen would make a difference in my writing but the high quality understated function and minimalist design is the best. The size fits comfortably in my small hand, the ink refill lasts me maybe a month? Since I use all 3 ink colors it depends on which ink color I’m using ….

I am a big fan of writing supplies and a .38mm pen!! So I saw this and thought why not?! I don’t usually like gel pens but this is great! Smooth writing and doesn’t glide using just the right pressure. The texture and feel make it an easy grip. Love the pastel colors and price… can’t beat it!! Oh and LoVe ❤️ the clip!! It’s great to fidget with.

I lost the first one so I bought a second one because I loved the first one so much. This pen comes in a zillion different colors, writes so smooth. All you have to do is look at the reviews. This pen is awesome. And I carry a very small purse so this pen fits perfect. I love it. Oh and its very comfortable in your hand even though its small.

TL;DWR. The pen writes fantastically and has great ink, the body is above average in build quality and ergonomically very comfortable. However the spring isn't changeable and for me was squeaky right off the bat. The Uni-Ball One P is an interesting little pen with it's stocky design. The overall build quality is quite nice and It's no heavier or lighter than most pens; I found it quite comfortable to hold even with larger hands. The plastic body itself feels fairly premium? Definitely not cheap feeling but also not completely outstanding, with the walls of the pen being just a tad too thin for it's extra circumference, leading the barrel to have some "hollowness" to it. Which overall makes it feel less dense than you think it would. However the thicker body means it doesn't need any sort of grip or rubber to hold very comfortably. The click of the pen feels disappointingly soft and the spring is quite squeaky (more on the spring later) but the actual writing experience is very nice and the ink is incredible, outperforming my previous favorite ink from Energel. It's incredibly dark, very smooth flow and very very quick to dry (like seriously the only way I could get it to smear was inking a circle in completely and then very quickly running my finger across). The pen clip being made of metal and separate from the pen body is also very nice, it means you don't have to worry about a plastic piece that can break off as the metal would bend before it would break. Now about that spring... Well it's hidden, and not removable from what I can tell, and the same goes for the push button/thrust device. Which comes with both a pro and a con, the pro being you can't lose anything when opening the pen to change ink. The con being you can't replace the spring, period. Which I could actually see being a great thing if you're giving this to a kid who likes taking stuff apart. But if you're like me and want to be able to change the spring it's pretty unfortunate. Especially since it doesn't sound all that great out of the box, though it might be smoothed out with a little mechanical keyboard lube. Again, overall a great little pen. Very aesthetic appearance wise and also comfortable to hold. With the ink being the true hidden gem of this pen. (But I gotta dock a star for the squeaky spring)

Very small, cute, and clicky. It makes for a wonderful professional fidget toy, and clips easily to your pocket. It writes smoothly. This wins best pen!

Great pen! Love the size and how it writes. Very smooth

Love this product! I am going to buy more in a different color and some refills, this is the best and cutest pen ever! So easy to use, and doesn’t make a loud click noise which can be an issue when having ADHD. The pen is smooth when writing on just about any paper I’ve noticed with minimal skipping. It fits so well in my small hand and doesn’t cause any issues. I also love the clip on the pen too!!!!

The early One pens from '21-'22 would skip and railroad excessively, offsetting any gains from the darker look the pigmentation was intended for. The One F was an improvement over the original One which looked streamlined, felt fine to use, and wrote dark lines. The F wrote more consistently and had more weight in the front, where the one was more evenly distributed. Like the One F, the One P is built with a metal front tip and a smooth barrel. There is no grippy section in the front, unlike the original One. The One P certainly is pocket-sized, as intended. This may be a problem for the largest hands, but the barrel isn't slippery. It is threaded together in the middle and the ink cartridge is almost the entire length of the pen. I received a 2024 cartridge and have had no problems with the ink flow in the 0.5mm size. It does look very slightly darker than the smaller 0.38mm ink cartridge. Overall, I'm surprised the '24 model is writing so much better than the early One inks. Most likely, a reformulation occurred even after the early run of One P. The pocket clip is strong, but may not be tight enough for retention through constant leaning forward. The only thing left to improve after making sure the new ink is consistent across the models is maybe a deeper carry pocket clip. This would probably require a redesign to avoid looking like the original Zebra Sarasa Grand, where the clip was could interfere with the nock operation.