Kamenoko Scrub Brush Day

What Is Kamenoko Scrub Brush Day?

Every July 2nd is "Kamenoko Scrub Brush Day" (たわしの日, Tawashi no Hi) in Japan. On July 2, 1915, Nishio Shōzaemon (西尾正左衛門), the first president of Kamenoko Tawashi Nishio Shoten (亀の子束子西尾商店), was granted a patent for the "Kamenoko Tawashi" (亀の子束子, "turtle-child scrub brush") — the iconic dome-shaped natural-fiber scrubbing brush that has been a fixture of Japanese kitchens for over a century. The Kamenoko Tawashi, made of natural plant fibers such as palm fiber bundled with wire into a shape suggestive of a turtle's back, is one of Japan's most enduringly successful domestic goods and its basic design has changed little in more than a century. The company registered July 2 as Tawashi Day with the Japan Anniversary Association.

The Invention of the Kamenoko Tawashi

The Kamenoko Tawashi was created by Nishio Shōzaemon (西尾正左衛門), founder of Kamenoko Tawashi Nishio Shoten, a company founded in 1907. He developed the design as a more effective and durable alternative to the loose bundles of straw or fiber that had previously been used for scrubbing pots and floors. The dome shape concentrates scrubbing force, the natural fibers are tough enough to remove stubborn stains but gentle enough not to damage surfaces, and the wire core maintains the brush's shape through heavy use. The design was so successful that the company has continued making it in essentially the same form ever since.

A Century of Unchanged Design

The Kamenoko Tawashi's longevity as a product is a testament to the quality of its original design. In an era when most consumer goods are redesigned, rebranded, and replaced on short cycles, the Kamenoko Tawashi has been made by the same company using essentially the same fiber and wire construction for over a century. It has acquired the status of a "long seller" (ロングセラー) — a product so well-suited to its purpose that improvement seems unnecessary. It has also become a familiar icon of timeless Japanese functional design.

The Tawashi in Japanese Kitchen Culture

The tawashi occupies a specific niche in Japanese kitchen culture: ideal for scrubbing root vegetables (especially the rough skin of burdock root, gobō), cleaning cast-iron pots, and scrubbing bathroom tiles. Its natural materials are eco-friendly — biodegradable and made from a renewable resource — making it increasingly popular with environmentally conscious consumers as a plastic-free alternative to synthetic scrubbers.

Fighting Imitations

• Imitations: According to the company, the tawashi sold slowly at first, but once its convenience became known, sales grew sharply — and imitations soon followed. Obtaining the patent was one of the ways the company tried to protect its product.
• Trademark: In 1908, the company registered the name "Kamenoko Tawashi" and its turtle mark as trademarks.
• Packaged goods: The company was ahead of its competitors in selling tawashi in packaging, an idea said to have been inspired by the wrapping of soap, which was a luxury item at the time. The turtle mark and orange package remain the brand's trademark look today.

Fun Facts

• The patent date: Tawashi Day marks July 2, 1915 (Taishō 4), when the patent for the tawashi was granted — about eight years after the company was founded.
• Quality first: According to the company, Nishio Shōzaemon believed that "good products will always sell" and focused on high-quality tawashi from the very beginning.