Est. 2026 · Price: FreeEditor-at-large: The Hedgehog

Stationery Times

Brand: MUJI

MUJI Compact Fountain Pen: 11 cm, 0.5 mm, Cartridges

Compiled from 3 sources; we haven't tested this product ourselves yet. How we research

Quick answer

The MUJI Compact Fountain Pen is a short capped fountain pen with a clip and a 0.5 mm nib. MUJI USA lists it at 11 cm (4.3 in), includes two black ink cartridges, says only MUJI's compact cartridges fit, and gives China as the origin.

On this page10 sections
MUJI Compact Fountain Pen capped, drawn to scale at 11 cm with a clip
The capped compact fountain pen at MUJI USA's listed 11 cm (1 mm = 7.95 px). Original illustration made for this guide. © Stationery Times.

Product facts

Product
MUJI Compact Fountain Pen
Brand
MUJI
Brand origin
Japan
Made in
China*
Material
Polycarbonate body, ABS resin parts (per MUJI USA)
Good for
Price range
$$$5–20 per pen (multi-packs divided by the count)
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Notes on these facts
  • Made by Ryohin Keikaku Co., Ltd.. Made in China: MUJI USA's product details give "Country/Region of Origin: China". Source. Price: example listing.
  • How we test and disclose samples: How we test stationery.
  • Price bands are typical US retail, checked October 2026.

Key takeaways

  • MUJI USA lists the pen at 4.3 in (11 cm) long with a 0.5 mm nib and a clip, with a polycarbonate body and ABS resin parts.
  • It comes with 2 black ink cartridges, and only the compact fountain pen cartridges (5-pack, black) fit it.
  • MUJI says it is the perfect size for an A7 notebook; line thickness varies with writing pressure.
  • MUJI USA gives China as the origin, and the pen is in our $$ band ($5–20).
  • MUJI USA's care note says to avoid shaking the pen to prevent staining.

What is the MUJI Compact Fountain Pen?

It’s a short, capped, cartridge-filled fountain pen with a 0.5 mm nib, made to go with MUJI’s A7 notebooks. MUJI USA calls it a compact version of its fountain pen, cute and portable. MUJI is the brand of Ryohin Keikaku, the Japanese retailer.

It comes with 2 black ink cartridges, so you can write the day it arrives.

MUJI compact fountain pen specs

Spec Value
Maker MUJI (Ryohin Keikaku Co., Ltd.), Japan
Type Cartridge fountain pen with clip
Length 4.3 in (11 cm)
Nib 0.5 mm (line varies with pressure)
Materials Polycarbonate body, ABS resin parts
Included 2 black cartridges
Barcode 4550583693404
Made in China (MUJI USA)

MUJI USA gives no weight or barrel width, so the barrel in our drawing is drawn by eye.

Who is the MUJI compact fountain pen for?

It suits someone who wants to try a fountain pen cheaply, in a size that fits a small pocket.

  • Everyday carry: it is 110 mm (4.3 in) long, and MUJI USA says the clip fits a pocket, lanyard or closed notebook.
  • First pen: it is in our $$ band, uses cartridges, and comes with 2 black ink cartridges, per MUJI USA.

Skip it if you want to use bottled ink or a converter: MUJI USA lists none for this pen.

The 11 cm MUJI compact fountain pen standing beside an A7 notebook 10.5 cm tall, to scale
The pen is half a centimetre taller than the 10.5 cm A7 notebook it is made for (1 mm = 2.4 px). Original illustration made for this guide. © Stationery Times.

Which cartridges fit?

Only MUJI’s compact fountain pen cartridges fit, says MUJI USA. It sells them as a black 5-pack. MUJI’s longer fountain pen cartridges don’t fit, and MUJI USA warns the same of its aluminum fountain pen set.

Standard international cartridges are a different shape, so don’t assume they will fit. Our best fountain pen ink cartridges guide covers the common types.

Does it fit the A7 notebook?

MUJI USA says it is the perfect size for an A7 notebook, and sells a Compact Notebook A7 with a pen loop. The pen is 11 cm long and the notebook 10.5 cm tall, so it stands half a centimetre taller than the notebook, per the listed sizes.

How does it compare with MUJI’s other compact pens?

It costs more than the gel pen and holds ink you can’t change in colour as easily.

Compact fountain Compact gel pen
Length 11 cm 11 cm
Nib 0.5 mm 0.5 mm
Refill Compact cartridges Not stated
Price band $$ $
Made in China China

For a first fountain pen from other makers, see our best fountain pens for beginners.

Where is it made, and what does it cost?

In China: MUJI USA gives China as the country or region of origin. The pen is in our $$ band ($5–20). MUJI USA sells it as Final Sale, with no refunds or exchanges; we read the page on November 1, 2026, and prices change.

Frequently asked questions

Does the MUJI compact fountain pen come with ink?

Yes. MUJI USA says it comes with 2 black ink cartridges.

Which cartridges fit the MUJI compact fountain pen?

MUJI USA says only the compact fountain pen ink cartridges fit it, and sells them as a black 5-pack. Its longer cartridges don't fit.

How long is the MUJI compact fountain pen?

MUJI USA lists 4.3 in (11 cm) with the cap on.

What size is the MUJI compact fountain pen nib?

MUJI USA lists a 0.5 mm nib and says the line thickness can vary with writing strength.

Is the MUJI compact fountain pen made in Japan?

No. MUJI USA lists China as the country or region of origin.

Can you shake a MUJI fountain pen to start the ink?

MUJI USA says to avoid shaking the pen as much as possible, to avoid unnecessary staining.

Can I return a MUJI pen bought online?

MUJI USA marks it Final Sale, with no refunds or exchanges, on its product page as we read it.

Sources (3)

  1. MUJI USA: Compact Fountain Pen (length 4.3 in / 11 cm; nib 0.5 mm; polycarbonate and ABS resin; 2 black cartridges; compact cartridges only; China; read in full November 1, 2026)
  2. MUJI USA: Compact Fountain Pen Ink Cartridge Refills - Black (5 Pack) (listing seen in the stationery collection)
  3. MUJI USA stationery collection (product list, read November 1, 2026)

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