When textile designer Katsuji Wakisaka sketched the "SO-SU-U" pattern in 1995, he took the most mundane characters in human communication, the numerals zero through nine, and turned them into Kyoto label SOU・SOU’s defining visual signature. Thirty years later, that same hand-drawn font is doing the heavy lifting on a new everyday stationery collection with Kokuyo.

Textile designer Katsuji Wakisaka painting colorful floral patterns on paper with a fine brush and watercolors.

Katsuji Wakisaka - Textile designer for SOU・SOU

SOU・SOU is a Kyoto-based textile brand that incorporates traditional materials and techniques into modern lifestyle products. They produce and sell a wide range of items, including the world's only domestically produced tabi (traditional Japanese split-toe socks), as well as Japanese and Western clothing, accessories, and Japanese sweets. Furthermore, they are expanding the possibilities of Japanese textile design through collaborations with companies in various fields.

SOU・SOU logo featuring a stylized number pattern on a white background.

The SOU・SOU storefront located in Kyoto, Japan

Rather than leaning into SOU・SOU's usual palette of saturated colors, this collection pares everything back to high-contrast black and white. The result puts the graphic geometry front and center across Kokuyo's standard workhorse supplies, from Soft-Ring notebooks to Dotliner adhesives, giving utilitarian desk essentials a stark, modernist identity that feels distinctly Japanese.

Katsuji Wakisaka's SO-SU-U pattern featuring black scattered numbers on a plain white background.

Katsuji Wakisaka's "SO-SU-U" pattern created in 1995

The collaboration will be between the Kyoto-based textile brand with Japanese stationery giant KOKUYO Commerce Co., the Shanghai overseas branch of KOKUYO CO., Ltd., in Japan. The collaboration will be featuring 11 items in total. The release of the collaborative products will be launched in Japan and will be available on SOU・SOU's online shop and domestic stores, excluding the SOU・SOU San Francisco store.

The Lineup: Everyday Desk Utilities

Rather than inventing esoteric desk ornaments nobody needs, the collection sticks to the tools people actually use until they run out of ink or tape:

Three Kokuyo Campus Softring notebooks in various sizes featuring a white cover with black numerical patterns.

Kokuyo's Softring Notebook with SOU・SOU design will come in A7, A6, A5, and B5 in either Black or White

Soft-Ring Notebooks (¥280–¥440): Kokuyo’s squishy, wrist-friendly resin spiral rings get the numeral treatment across four formats, from pocket-friendly A7 and A6 to everyday desk sizes in A5 and B5.

Two Kokuyo Campus notebooks in black and white featuring a white numeric pattern on a plain background.

Kokuyo's 8-ring binder will be available in both A5 and B5

8-Hole Smart Ring Binders (¥1,100–¥1,320): Ultra-slim, fold-back binders available in A5 and B5, keeping loose-leaf pages organized without the bulk of traditional multi-ring hardware.

Kokuyo Campus stationery set featuring a black pen and various white and black pencil cases with numeric patterns.

SOU・SOU & Kokuyo focused on Katsuji Wakisaka's iconic monochromatic signature.

Gel Ink Pens (¥330): Retractable 0.5 mm gel pens finished in black and white barrel designs with crisp, non-skipping black ink.

Desk Adhesives & Correction (¥380–¥440): Compact Dotliner tape glue and tear-free correction tape wrapped in monochrome number casings.

Black and white Kokuyo Campus fabric pouches featuring a white numeric pattern and blue brand label.

Stand-Up Pencil Cases & Pouches (¥1,650–¥2,200): Upright desk cases and zip organizer pouches designed to stand open on narrow tables or slide flat into a commuter bag.

The collection is available through SOU・SOU’s official online boutique (sousou.co.jp) and in-person. Their website does support the English language and will ship overseas too!