Maker: Muji (or, at least, the company it’s sold by).
I cannot say that I’ve ever been inside a Muji store, but I have some friends who seem to get to Japan at uncommonly frequent intervals– this derives from one of their trips. The packaging has nothing like a model name on it; the kanji which romanizes as “arumi marujiku mannenhitsu” simply means “aluminum round-bodied fountain pen,” which is a pretty complete description but hardly a name. I find that it appears on the company’s US website under much the same name, and here we see a difference between Muji and Ikea, as the former doesn’t bother with coy names like “Pæn” or “Scrÿbbl”, but applies bland descriptions as names.
There’s not a mark on the body to even identify it as coming from Muji, or anywhere else, although the point has a script “F” on it which likely means that part at least is made for them by Fuliwen, a Chinese pen- maker. While less interesting in shape, it’s similar to the Lamy 2000 in its utilitarian nature. One may find onlookers asking how it’s possible to write with an X-Acto knife. The older version of the Round Aluminum Pen has a rather more traditional section.
Happily, it is equally utilitarian in its writing aspect– a hard point, but smooth and willing. Like some other low-end Japanese pens I’ve encountered (both Sailor and Pilot offer examples), this one is set up to allow the cartridge to be swapped without removing the cap– the joint is at the back of the knurled area, and the cap fetches up against the front of it. This is both clean (less likelihood of touching the point in the process) and sensible (reduced risk of misplacing the cap, however briefly).
Production Run: The older version I cannot say; back at least to 2000, and probably before. The newer item is c. 2005 – present. I date them thus because the donor of mine owns the older pattern from a previous Japan trip, so there was a change-over about 2005.
Cost When New: $15.50 in the 2011 listing.
Size: 13.8cm capped, 16.2 cm posted, 12.5 cm uncapped (newer version).
Filler: Cartridge, capacity approx. 0.6 ml or 1.4 ml (international pattern).
If you are relying on the preceding information to win a bet or impress a teacher, you should read the site’s scholarly caveat. Remember, this is the internet, and it’s full of bad information.