The archive · Small Business & Money · Operational decision · 2012–2025
Sunday Savon: a Kobe soap shop open one day a week, with patrons nationwide
One craftsman, soap that keeps its moisture, and a shop that opens only on Sundays: customers across Japan make the trip to Kobe for it.
Sunday Savon (KoLabo)
What it had to solve
After 20 years inventing formulas at Procter & Gamble Japan, Kojo Tanaka saw good products shelved because factories could not make them profitably. He left to sell his own soaps, alone and by hand.
How it works
Kojo Tanaka spent about 20 years in research and development at Procter & Gamble Japan, inventing base creams and chasing 'golden formulas.' Again and again, products he was confident in were not commercialized: mixing large volumes made them too costly to manufacture, so factory economics decided what customers ever saw.
Unsatisfied as a craftsman, Tanaka went independent and chose soap — a product central to skincare since antiquity — as the pillar of his business. In 2012 he prototyped Water-in Soap, which is not dried out but matured in gauze so it keeps moisture and fresh scent, and in 2013 he opened Sunday Savon on the second floor of a building in Kobe's Sakaemachidori district.
Because he runs every stage himself, from development to sales, Tanaka opens the store only on Sundays, 12:00 to 18:00. The three-tatami shop sells bars in three sizes from 990 yen, is not sold online, and patrons across Japan travel to Kobe for it; he compares the shop to a beloved neighborhood bakery rather than a cosmetics counter.
Why it lands
- Opening one day a week turns a purchase into an event, so the constraint itself markets the shop.
- The product defends the price: moisture sealed in by a non-drying process is hard for mass producers to copy cheaply.
- The maker is the storefront: customers meet the craftsman face to face, which department-store cosmetics never offer.
- Refusing online sales and daily opening keeps quality constant — the same recipe for over ten years.
What it did
A shop the size of three tatami mats draws patrons from across Japan who can only buy the soap in Kobe on a Sunday; the recipe has not changed in more than a decade and customers rely on it long-term.
What you can take
A capacity constraint can be the positioning: instead of scaling down quality, make the scarcity deliberate — a one-day shop turns shopping into an event and the maker into the store.
Since then
By late 2024 Tanaka, then 57, still ran the shop alone and had not changed his recipe for more than a decade; The Asahi Shimbun reported that customers across Japan kept coming despite the shop being closed to online sales. A seasonal release in late 2025 confirmed Sunday Savon still opened only on Sundays, 12:00–18:00. Tanaka's ambition is not a chain: he wants Kobe's Sakaemachidori and Kaigandori districts to become a hub of independent cosmetics shops run end to end by their makers.
Sources
- Tiny Sunday-only soap shop has patrons across Japan
- Sunday Savon's Christmas seasonal Water-in Soap release
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