• WADEN Image


Many of Japan's cultural treasures originated all over Japan and have been passed down and inherited throughout the generations.
Among them are traditional crafts that have now become world renowned, as well as certain crafts that are only known locally.
Regardless, both are equally significant and hold immense value within the Japanese culture.
What makes these "Japanese treasures" so special is that they are able to surpass all generational barriers and remind us of the "Japanese spirit" that we believe is deeply rooted in our DNA.
These Japanese crafts provide us with a sense of warmth and comfort, knowing that there is so much tradition and meaning attached to each and every price.
By sharing our love of traditional crafts, we feel an enormous sense of pride for our beloved country.
Here at Waden, it is this love for Japan that propels us to disseminate the Japanese spirit, culture, and traditions with the rest of the world as well as ensure that these "Japanese treasures" continue to be preserved by the following generations.

Artifact Information

Artifact NameOgatsu Genshoseki : Stonework
History This sturdy black slate, mined in the town of Ogatsu in Ishinomaki, Miyagi Prefecture, originally formed as part of a geological strata two to three hundred millions ago.

It was formed by movements in the Earth’s crust during the early Cretaceous period, where the clay and mud that settled at the bottom of a deep inland sea was turned into slate.

That sea – known as the Tome Sea – no longer exists today, but the deep black slate known as Genshoseki slate remains.

Genshoseki’s noteworthy black color is the result of carbonaceous material in the clay.

It is lustrous and homogenous in its particle distribution, and highly resistant to compression, warping, and water absorption, which protects it both from chemical changes and the ravages of time.

These properties make it useful not just for inkstones, but for building material such as roof tiles and walls, as well.

*In 1985, Ogatsu Inkstones were declared a traditional craft by the Minister of Economy, Trade and Industry.

Ogatsu Genshoseki


Manufacturing Method

1. Excavation
Heavy machinery is used to shave away at the seemingly inexhaustible supply of slate rock in the mountains near Ogatsu.

The rocks are then split using jack hammers and pile drivers, to a size that can fit into trucks.

*The expertise of an artisan is required to figure out how the pile driver could split the rock.

2. Major shaping
The rocks are brought from the mountain in trucks, then cut into appropriate sizes using diamond cutters.
3. Minor shaping
The appropriately sized rocks are cut into the sizes necessary for their products.
4. Sanding
The Genshoseki are pressed against a rotating disc full of sand and water to smooth out the product’s underside.

*A light hand is required when determining the power and angle to be used in this process, as mistaken wear and tear on the underside can result in an unstable, defective product.

5. Carving
This is a traditional technique handed down for 600 years among Ogatsu Inkstone artisans, and an important process for ensuring the quality of Ogatsu Inkstones.

*Human hands alone are not strong enough to hollow out the slate, so the artisan employs a steel blade with a long handle that they can press against their shoulder.

6. Finishing
Final shaping adjustments are made, and the product is polished.

*If a mistake is made during this step, it must be restarted from the carving stage.

●Inkstones and other products, such as tableware, crafts, all undergo slightly different production processes, but what all Genshoseki products have in common is the hard work and experience required to make them.

Ogatsu Inkstones

ex_View05 Ogatsu Inkstones are Japan’s best inkstone brand, with a rich 600 year history.

They have been loved by people of culture all over Japan for centuries, including the famous one-eyed Warring States Era general, Masamune Date.

*Inkstones are a stationery tool, made from rock or tile, and used for grinding ink in water.
Along with paper, brush, and ink, they are considered to be one of Japan’s “Four Treasures of the Study.”

Business revival support efforts

2011 Tohoku earthquake and tsunami

"Ogatsu is a small town with a population of just 4000, located in Ishinomaki, Miyagi Prefecture.

Its adjacency to the ocean has led to a thriving fishing industry.

It is also a producer of Genshoseki and the originator of Ogatsu Inkstones, which it has crafted for over 600 years.

These inkstones have been designated a traditional craft by the Minister of Economy, Trade, and Industry.

On March 11th, 2011, a magnitude 9.0 earthquake – the most powerful earthquake ever recorded in Japan – caused a massive tsunami which killed 250 people and destroyed 80% of the structures in the town.

Two and a half years into the reconstruction, many people are still forced to live in temporary housing, and the center of Ogatsu, which faces the bay, has been designated a prohibited area, open for business but not for residency.

This is one of the many problems along with mass relocations and road repairs being dealt with in the restoration of the town.

Waden, Inc is taking part in the restoration efforts, supporting businesses by helping to provide and maintaining the equipment necessary for production.

We realize that true rebuilding requires continuous and flexible support, and it is with this belief in mind that we continue to promote the sale of Ogatsu Genshoseki products."


The roof of the Tokyo Station

As a highly prized building material, Ogatsu Genshoseki was used in the roof of the Tokyo Station building during its original construction in 1914.

A century later, in October 2012, when the building was refurbished, it was once again incorporated in the natural slate used for the roof’s dome portions.

Unfortunately, the earthquake made it impossible to have all of the roofs be made of Ogatsu slate, but local businesses all worked together on the project as a symbol of Ogatsu’s reconstruction.


Location & Address

■ 株式会社 和伝: WADEN
Postal code
2-1-3 Tekkodori Urayasu Chiba
Business hours
11:00 - 18:00