Sikigu Fumibako: Paper Letter Box With Pen Tray

Two Sikigu Fumibako paper boxes from above, drawn to scale: L at 275 × 198.5 mm and S at 198.5 × 137.5 mm, each with a pen tray — Sizes L and S from above at one scale (1 mm = 1.72 px); colors sampled from the maker's photos, tray drawn by eye. Original illustration made for this guide. © Stationery Times.

Product facts

Product

Sikigu Fumibako

Brand

Sikigu

Brand origin

Japan

Made in

Not stated^*

Material

Paper

Price range

$$$$20–75 per item

Colors

Robai

Rate it

No ratings yet. Be the first to rate this product.

Notes on these facts

Made by Taisei Shiki Mfg. (TAISEI Co., Ltd.). Country of manufacture not stated: The maker's product page gives no country of manufacture. Check the packaging. Source. Price: example listing.
Colors: names per Taisei Shiki (maker's Fumibako page and product photos), checked November 4, 2026. The maker lists three variations, Robai, Sakura and Fuji. Its photos show a mauve-brown box and a pale one; we could not tell which name belongs to which, so the tints are not matched to names. Tints are representative, not measured. Shops stock different colors.
How we test and disclose samples: How we test stationery.
Price bands are typical US retail, checked October 2026. Conversions to US dollars are approximate, at October 2026 rates (US$1 = ¥158 = ₩1,330 = NT$32.5 = CN¥6.7 = SEK 9.9 = DKK 6.7 = ₺49.6 = C$1.41 = A$1.43 = CZK 21.7; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).

Key takeaways

Taisei Shiki lists two sizes: L at W275 × H66.5 × D198.5 mm and S at W198.5 × H66.5 × D137.5 mm, in paper, with a movable pen tray included.
The folds are cut with V-shaped grooves, a technique the maker says is traditionally used for Japanese wooden kiri-bako storage boxes, so the edges stay sharp and the boxes stack.
The maker pitches it for storing letters and other sentimental items, and lists three colors.
The maker lists three variations, Robai, Sakura and Fuji; we could not match its photos to those names.
The Journal Shop in the UK listed S at £47.99 (about US$63, $$$ band) and L at £67.99 (about US$90, $$$$ band) on November 4, 2026.

What is the Sikigu Fumibako?

It is a stiff paper box for letters, with a pen tray that moves. Sikigu is the paper-products brand of Taisei Shiki Mfg. (TAISEI Co., Ltd.) in Higashiosaka, Osaka. The Fumibako, whose name is the Japanese word for a letter box, is a rigid paper box with sharp edges. The maker cuts V-shaped grooves into the folds, a technique it says is traditionally used for Japanese wooden storage boxes called kiri-bako, and combines it with handcrafting to make a box that stacks easily.

We read the maker’s English page on November 4, 2026.

The maker’s emphasis is on the beauty of the paper and the sturdiness of the box. For other desk pieces, see our best desk accessories.

What are the sizes and what is inside?

Two sizes, both 66.5 mm tall, with a movable pen tray.

Spec	Size L	Size S
Width	275 mm	198.5 mm
Height	66.5 mm	66.5 mm
Depth	198.5 mm	137.5 mm
Material	Paper	Paper
Includes	Movable pen tray	Movable pen tray
Price (UK, November 4, 2026)	£67.99 (about US$90)	£47.99 (about US$63)

Size S’s width, 198.5 mm, equals size L’s depth. The maker gives outside dimensions only, so inside space is smaller by an amount it does not state. By outside size, an A4 sheet (210 × 297 mm) is longer than either box and cannot lie flat in either. An A5 sheet (148 × 210 mm) is within L’s 275 × 198.5 mm footprint only when turned sideways, and not within S’s, so assume folded letters and cards for S. Our notebook sizes chart lists the standard paper sizes if you want to compare, and we have not tested any fit.

Front views of both sizes at the same scale; both are 66.5 mm tall. Original illustration made for this guide. © Stationery Times.

Which colors does it come in?

Three variations: Robai, Sakura and Fuji. The maker’s photos show one box with a mauve-brown outside and one with a pale outside, and we could not tell which photo belongs to which name, so we do not attach a color to each. The Journal Shop sells Robai in L and Sakura and Fuji in S, so not every color may be sold in both sizes there; that is a retailer’s range, not the maker’s statement.

Who is the Fumibako for?

It suits someone who keeps paper keepsakes, because the maker designed it for letters and sentimental items and it is 66.5 mm tall. It also holds pens: the movable tray is meant for writing tools.

It is not a document file. An A4 sheet cannot lie flat in either size, and the maker states no load limit or inside dimensions. We did not use a fit tag because none of our use tags describes storing keepsakes honestly.

What does the maker not say?

Several things a buyer would want. The page gives no paper type or thickness, no inside dimensions, no weight, no load limit and no lid or closure details beyond the sharp V-cut edges. It does not say whether the pen tray lifts out or only slides, which of the three colors is mauve and which is pale, or where the box is made. We have not handled one, so we cannot add any of this from experience; the hands-on note at the foot is where that test would go.

What does it cost, and where is it made?

It sits in our $$$ band for S and $$$$ for L. On November 4, 2026 The Journal Shop in the UK listed S at £47.99 (about US$63) and L at £67.99 (about US$90). Prices change; we did not check other sellers. The maker does not state a country of manufacture on the page we read.

To pair it with other gifts, see our best stationery gifts under $100 and our Sikigu Swing Letter guide, a small card from the same maker.

Frequently asked questions

What does Fumibako mean?

It is the Japanese word for a letter box, which the maker uses as the product name. The maker's page describes it as a box for storing letters and sentimental items.

How big is each size?

L is 275 mm wide, 66.5 mm tall and 198.5 mm deep; S is 198.5 mm wide, 66.5 mm tall and 137.5 mm deep. Both are listed by the maker.

What is a V-cut box?

The maker says V-shaped grooves are carved into the folds so the edges come out crisp and the box is sturdy. It borrows the method from Japanese wooden kiri-bako boxes.

Is the pen tray removable?

The maker says the box includes a movable pen tray. It does not say whether the tray lifts out, so check before you plan around that.

Can the boxes be stacked?

The maker says the V-cut and handcrafting technique creates a product that stacks easily. It gives no weight limit.

Which colors are there?

Robai, Sakura and Fuji. The maker's photos show a mauve-brown outside with a pale inside on one box and a pale outside on another, but we could not tie the photos to the names.

How much does it cost?

The Journal Shop in the UK listed S at £47.99 (about US$63) and L at £67.99 (about US$90) on November 4, 2026. Prices change, and we did not check other sellers.

Sources (3)

Plain-text version for AI agents: sikigu-fumibako.md · Spotted an error? See how we check facts.