Tokoname Mogake “Tide Trace” Kyusu

At first glance, the reddish-brown lines running across this teapot might look hand-painted. They are actually created using Mogake (藻掛け), a traditional Tokoname technique in which real sea plants are placed directly against the clay before the teapot enters the kiln.

During firing, the plant material burns away, but minerals and salts from it react with the surface of the clay, leaving behind irregular reddish and earthy traces.

The sea plant disappears.

Its shape remains permanently recorded in the teapot.

What Is Mogake?

Mogake has been practiced in Tokoname (常滑) since the Edo period.

Traditional Tokoname sources describe the technique as wrapping amamo (アマモ) around the unfired clay before firing. Amamo is commonly translated as eelgrass or seagrass. Despite often being referred to simply as “seaweed,” it is actually a flowering marine plant that grows in shallow coastal waters.

The salt contained in the plant reacts with the clay during firing, causing the areas it touches to develop distinctive hi-iro (緋色), or reddish-orange fire colors.

According to Tokoname's official pottery sources, the technique is traditionally credited to potter Ina Chōza (伊奈長三) during the Tenpō era of the 1830s–1840s. Early examples were made by placing dried marine plants over Tokoname white clay before firing.

Because the plant is placed by hand and burns away in the kiln, it is essentially impossible to create exactly the same pattern twice.

A Decoration Born From Tokoname's Coast

Mogake makes particular sense in Tokoname.

Tokoname sits directly on Ise Bay in Aichi Prefecture, and its pottery culture developed alongside this coastal landscape. Even today, Tokoname tourism materials specifically describe Mogake as a technique characteristic of the seaside pottery town: marine plants are placed against the clay and fired to create the decoration.

That makes the marks on this pot more than an abstract pattern.

They connect the piece directly to the geography and pottery history of Tokoname.

Why This Shape?

This kyusu has a low, broad body with gently rounded walls, rather than the taller profile found on many Chinese teapots.

That proportion is particularly useful for Japanese green tea.

The wide interior allows sencha and other needle-shaped Japanese tea leaves to spread across the bottom of the pot instead of becoming tightly piled together. Water can move easily through the leaf bed, helping produce a more even infusion.

The lower profile also releases heat somewhat faster than a tall, compact pot. This can be useful for teas such as:

• Sencha

• Kabusecha

• Fukamushi sencha

• Gyokuro, when brewed at lower temperatures

• Lighter Japanese steamed teas in general

Its large lid opening is another practical detail. Japanese green tea leaves can become very soft after brewing, so a wide opening makes it considerably easier to add the leaves and clean the pot afterward.

Why Tokoname?

Tokoname-yaki (常滑焼) has approximately 1,000 years of ceramic history and is recognized as one of Japan's Six Ancient Kilns (日本六古窯). Teapot production became particularly important during the Edo period as sencha culture spread through Japan.

Tokoname eventually became especially famous for the kyusu.

Traditional Tokoname teapots are usually assembled from separately formed components—the body, lid, spout, handle, and ceramic strainer—which must align precisely for good balance and a clean pour. The region became known for producing pots that are thin, lightweight, tightly fitted, and highly practical for everyday tea brewing.

What Is Special About Tokoname Clay?

Tokoname is particularly famous for iron-rich clay, especially the red shudei (朱泥) associated with traditional Tokoname kyusu.

The clay used by Tokoname potters is not limited to red shudei, however. White clay, reduction-fired clay, blended clay bodies, and other surfaces have long been part of the tradition. In fact, Mogake historically developed in connection with Tokoname white clay, making the pale body of a pot like this especially appropriate for the technique.

Tokoname's official pottery sources also traditionally associate the iron content of its clay with a rounder, softer presentation of Japanese tea, particularly reducing the perception of bitterness and astringency.

I prefer to think of that as a subtle characteristic rather than a reason to expect the clay to completely change your tea. The shape, leaf quantity, water temperature, and brewing time still have a much greater effect.

Why I Like This Pot

What makes this piece special is that nearly everything about it is connected to where it was made.

The side-handle kyusu form belongs to Japanese tea culture.
The low, open body makes sense for Japanese green tea.
The Mogake technique comes directly from Tokoname's ceramic tradition.
And the irregular markings are created with actual marine plants rather than printed decoration.

If you look closely at the reddish lines running across the body and lid, you are essentially looking at the shadow of a plant that disappeared inside the kiln.

That is what makes Mogake so beautiful: the decoration is not simply an image of nature.

Nature actually made the mark.