Koizago Ware (こいさごやき) Complete Guide｜History, Characteristics, and Kiln Information of Tochigi Prefecture’s Traditional Ceramics
Koizago ware (こいさごやき), produced in the Koizago district of Nakagawa Town, Nasu County, Tochigi Prefecture, is a traditional ceramic representing Tochigi Prefecture, continuing from the late Edo period. With distinctive colors such as the golden-gleaming “gold crystal glaze” and peach-colored “copper red glaze,” and an unpretentious yet refined appearance, it continues to be loved by many people today. This article comprehensively explains information about Koizago ware, from its historical background and technical characteristics to existing kilns and purchase methods.
What is Koizago Ware (こいさごやき)?
Koizago ware is pottery fired in the Koizago district of Nakagawa Town, Nasu County, Tochigi Prefecture (formerly Batoh Town). It has a history of over 190 years as a traditional craft, beginning when Tokugawa Nariaki (Retsukou), the daimyo of Mito Domain, discovered the ceramic clay of this area in Tenpo 1st year (1830), the end of the Edo period.
Koizago ware is designated as both “Tochigi Prefecture’s Top 100 Special Products” and a “Tochigi Prefecture Traditional Craft,” positioning it as one of Tochigi Prefecture’s representative ceramic production areas. It is characterized by a unique quality that possesses the delicacy of porcelain while being pottery, and this intermediate character becomes the individuality of Koizago ware.
The Koizago district is also recognized for membership in the “Japan’s Most Beautiful Villages” association, with traditional pottery culture being inherited in an environment rich in nature.
History and Origins of Koizago Ware
Deep Connection with Mito Domain
The relationship with Mito Domain is indispensable when discussing the history of Koizago ware. During the Edo period, the current Batoh district of Nakagawa Town belonged to Mito Domain territory. In Tenpo 1st year (1830), Tokugawa Nariaki (1800-1860), the 9th daimyo of Mito Domain, discovered high-quality ceramic clay in Koizago, which is considered the origin of Koizago ware.
Tokugawa Nariaki is known as a daimyo enthusiastic about domain reforms, and as part of his policy of promoting industry and commerce, he invested efforts in promoting pottery manufacturing. The ceramic clay discovered in Koizago was adopted as a raw material for the Mito Domain’s official pottery kiln, positioning it as an important industry for the domain.
Oigane Hikozo and the Opening of the Kiln
After Koizago ceramic clay began to be used at the Mito Domain’s pottery kiln, Oigane Hikozo, a native of the Koizago area, constructed his own pottery kiln, and Koizago ware developed into a full-fledged local industry. Oigane Hikozo is remembered locally as a person who laid the foundation for Koizago ware.
Initially developed under the protection of Mito Domain, Koizago ware underwent independent development as a private kiln after the Meiji Restoration and the subsequent abolition of the domain system.
From the Modern Era to the Present Day
From the Meiji period onward, Koizago ware has been inherited as a regional traditional industry. From the Showa to Heisei periods, as lifestyles changed and mass-produced goods became widespread, many traditional pottery production areas experienced decline, and Koizago ware also went through difficult times.
However, as the value of traditional crafts was re-recognized, and through efforts to make pottery suited to contemporary lifestyles, several kilns continue to operate today. Through Tochigi Prefecture’s designation as a traditional craft and utilization as a tourism resource, the tradition of Koizago ware is being passed on to future generations.
Characteristics and Techniques of Koizago Ware
Properties of the Ceramic Clay
The greatest characteristic of Koizago ware lies in the ceramic clay extracted from the Koizago district. This clay contains abundant kaolin (china clay), giving it the property of being denser and harder when fired than ordinary pottery.
Kaolin is a white clay mineral known as a raw material for porcelain, and the abundance of it in Koizago’s ceramic clay creates unique pottery that possesses the qualities of porcelain while being pottery. This “intermediate character between pottery and porcelain” becomes an important element distinguishing Koizago ware from other ceramic production areas.
Gold Crystal Glaze (きんけっしょうゆう)
The signature feature of Koizago ware is the “gold crystal glaze.” During the firing process, components in the glaze crystallize, appearing as golden-gleaming speckles on the surface of the vessel. These golden crystals are the “face” of Koizago ware, adding brilliance and refinement to the rustic earth texture.
The gold crystal glaze is created by the delicate balance of glaze composition, firing temperature, and cooling speed. Even within the same kiln, temperatures vary by location, so each vessel shows different ways the crystals appear, creating individual character. This unpredictability is valued as the charm of handwork.
The yellowish coloring with a golden tone is unique to Koizago ware and is known as a color not seen in other production areas.
Copper Red Glaze (しんしゃ)
Along with the gold crystal glaze, “copper red glaze” is what characterizes Koizago ware. Copper red glaze refers to a peach to deep red coloring obtained by reduction firing glaze containing copper. It shows various expressions from soft, slightly peach-toned colors to vivid crimson, depending on firing conditions.
Copper red glaze is one of China’s traditional ceramic techniques and has long been treasured in Japan as well. The copper red glaze of Koizago ware, combined with the rustic earth flavor, creates a warm and elegant atmosphere.
Other Glazes and Decorative Techniques
Beyond the gold crystal glaze and copper red glaze, Koizago ware employs various glazes. Celadon-type glazes, amber glazes, ash glazes, and other traditional techniques are used as the foundation, with each kiln pursuing independent research.
Decorative techniques such as brushwork and comb-marking are also employed, creating simple yet expressive vessels. In recent years, pottery with modern designs suited to contemporary dining tables is also being produced, pursuing both tradition and innovation.
Manufacturing Process
The manufacturing process of Koizago ware is basically similar to other pottery, but techniques adapted to the properties of Koizago’s unique ceramic clay are required.
- Clay preparation: Ceramic clay from Koizago is extracted, impurities are removed, and it is mixed with water and adjusted to appropriate firmness.
- Shaping: The vessel is formed using a pottery wheel, hand-building, or molds.
- Drying: Slow drying stabilizes the body.
- Bisque firing: First firing at around 800°C increases strength.
- Glazing: Glaze is applied. Glazes are selected according to the intended colors, such as gold crystal or copper red glaze.
- Final firing: Firing at approximately 1200-1300°C. This temperature range, firing time, and cooling speed determine the coloring of gold crystals and copper red glaze.
Koizago’s ceramic clay, containing abundant kaolin, makes managing firing temperature and shrinkage rate difficult, requiring skilled technique.
Existing Koizago Ware Kilns
Currently, only a few kilns inherit Koizago ware, each pursuing independent artistic styles while preserving tradition.
Koizago Ware Fujita Pottery
One of the representative kilns of Koizago ware, this long-established kiln has over 190 years of history. Primarily producing traditional gold crystal glaze vessels, it makes a wide range of items from everyday tableware to tea ceremony utensils. The workshop allows viewing and purchasing, making it possible to directly experience the appeal of Koizago ware.
Koizago Ware Ichikawa Kiln
This kiln works to inherit traditional techniques while creating vessels suited to contemporary lifestyles. Developing unique works that leverage the characteristics of the gold crystal glaze, it continues to communicate the appeal of Koizago ware as a Tochigi Prefecture traditional craft.
Other Kilns and Artisans
Small but distinctive pottery artists are active in the Koizago district and surrounding areas. Young artists pursuing contemporary artistic expression while learning traditional Koizago ware techniques are also appearing, and new possibilities for Koizago ware are being explored.
The Appeal and Uses of Koizago Ware
As Everyday Vessels
The appeal of Koizago ware lies in its rustic, warm appearance and high practicality. A wide variety of everyday tableware is available, including rice bowls, tea cups, plates, and bowls. While being pottery, it possesses the delicacy of porcelain, providing appropriate strength suitable for everyday use.
The brilliance of gold crystals adds color to the daily dining table, making ordinary meals feel special. Additionally, the earthy texture enhances the food, harmonizing with Japanese cuisine as well as Western dishes.
As Tea Ceremony Utensils
Koizago ware is also valued as tea ceremony ware. Utensils used in the world of the tea ceremony, such as tea bowls, water jars, and flower vases, are produced, and the simple yet refined colors are well-received as fitting the atmosphere of a tea room.
In particular, copper red glaze tea bowls are loved by tea practitioners, with their soft peach color creating a beautiful contrast with the green of matcha.
As Gifts
As a Tochigi Prefecture traditional craft, Koizago ware is popular as a gift. It is often chosen for life milestone gifts such as wedding gifts, housewarming gifts, and sixtieth birthday celebrations. Handcrafted vessels, each with a unique appearance, are appropriate for conveying special feelings.
As a Tochigi-produced item, it is welcomed both as a gift to local people and as a Tochigi souvenir to those from outside the prefecture.
How to Purchase Koizago Ware and Access Information
Direct Purchase at Kilns
The most reliable way to purchase Koizago ware is to visit the kilns directly. At kilns such as Fujita Pottery and Ichikawa Kiln, you can purchase works at galleries and sales spaces attached to the workshop. You can examine items in person to confirm texture and color, and hear explanations directly from kiln owners, which is also an attraction.
When visiting, it is recommended to confirm business days and hours in advance. Some kilns offer workshop tours, and viewing the manufacturing process deepens understanding of Koizago ware.
Retailers in Nakagawa Town
Koizago ware may be handled at tourist facilities and roadside stations in Nakagawa Town. You can obtain information about retailers from the town’s visitor information center.
Online Shops
Some kilns operate online shops, making it possible to purchase from distant locations. You can confirm photos and detailed information of works and place orders through the official websites of kilns such as Fujita Pottery.
However, since handcrafted vessels have individual differences even in the same product, it is recommended to see the actual item when possible.
Craft Shops in Tochigi Prefecture
Traditional craft shops and department stores in major cities in Tochigi Prefecture, such as Utsunomiya and Tochigi, may also handle Koizago ware. At facilities such as the Tochigi Prefecture Products Hall, traditional crafts from throughout the prefecture are gathered in one place, allowing you to select while comparing Koizago ware with other Tochigi-produced goods.
Access Information
Automobile access to the Koizago district is convenient. It is approximately 40-50 minutes by car from either the Yagaita IC or Nasu IC on the Tohoku Expressway. By public transportation, from JR Karasuyama Line’s Karasuyama Station, you would use bus or taxi service, but as service is limited, it is important to confirm schedules in advance.
Nakagawa Town is a region rich in nature, and you can enjoy hot springs and tourist attractions along with visiting Koizago ware kilns.
Koizago Ware and Tochigi Prefecture’s Ceramic Culture
Ceramic Production Areas in Tochigi Prefecture
Tochigi Prefecture has several ceramic production areas besides Koizago ware. Mashiko ware is widely known nationally as pottery representative of Tochigi Prefecture, and has many fans due to its connection with the folk crafts movement. Additionally, in areas surrounding Utsunomiya, known for Oya stone production, unique pottery culture has developed.
While smaller in scale compared to these areas, Koizago ware, through its historical connection with Mito Domain and its unique characteristic of gold crystal glaze, becomes an important presence demonstrating the diversity of Tochigi Prefecture’s ceramic culture.
Protection and Promotion as Traditional Crafts
Tochigi Prefecture operates the “Tochigi Prefecture Traditional Craft” system, working to protect and promote traditional crafts in the prefecture. Koizago ware is designated under this system, and support is provided for technology inheritance, successor development, and sales channel expansion.
It has also been selected in the “Tochigi Prefecture Top 100 Special Products,” and utilization as a tourism resource is advancing. Nakagawa Town also positions Koizago ware as a cultural heritage of the region, undertaking efforts in coordination with tourism promotion.
Cultural Value of the Koizago District
The Koizago district is a member of the “Japan’s Most Beautiful Villages” association, and its rich natural environment and traditional culture are valued. Koizago ware is part of the district’s identity, cherished by local residents.
Visiting kilns is not merely an opportunity to purchase vessels but also to experience the scenery and culture of this beautiful village.
The Future and Challenges of Koizago Ware
Successor Development
Like many traditional crafts, Koizago ware faces the challenge of successor shortages. Learning pottery techniques requires many years, and there are also difficult aspects to management and business.
Currently, some kilns are working to inherit technology and discover new practitioners by accepting apprentices or offering pottery classes. Additionally, young pottery artists who find appeal in Koizago ware and relocate to the area are bringing new energy.
Adaptation to Contemporary Life
While preserving tradition, pottery suited to contemporary lifestyles is required. Some kilns are working to improve practicality, such as developing dishwasher-safe glazes and producing microwave-compatible vessels.
In design as well, works incorporating contemporary sensibilities alongside traditional forms are emerging, and Koizago ware appealing to younger generations is being explored.
Information Sharing and Branding
Information dissemination using the internet and social media is also an important issue. To raise awareness of Koizago ware and communicate its appeal to more people, efforts are underway to enhance websites, strengthen social media communication, and reinforce online sales.
By clearly communicating Koizago ware’s unique characteristics such as “intermediate between pottery and porcelain” and “gold crystal glaze” and differentiating it from other production areas, efforts to enhance brand value are anticipated.
Utilization as a Tourism Resource
Efforts to communicate Koizago ware as a regional appeal in coordination with Nakagawa Town’s tourism promotion are also important. By enriching kiln-touring tours and pottery experience programs, developing tourism routes combining nearby hot springs and natural scenery, and increasing visits motivated by Koizago ware, growth is anticipated.
By connecting Koizago ware with the “Japan’s Most Beautiful Villages” brand, development as a unique tourist destination is expected.
How to Enjoy Koizago Ware
Points in Selecting Vessels
When selecting Koizago ware, first consider the purpose. For everyday tableware, prioritize size, shape, and usability. For tea ceremony utensils or appreciation pieces, select with emphasis on color and the expression of glazes.
Gold crystal glaze vessels each show different crystal expressions, so it is recommended to examine items in person and select those matching your preferences. Individual differences among items from the same kiln and firing are the charm of handwork.
Use and Care
For pottery like Koizago ware, it is recommended to perform “seasoning” before first use. Boiling in a solution of rice water or diluted wheat flour seals the fine pores in the clay, preventing stains and discoloration.
Washing as soon as possible after use and drying thoroughly is the secret to longevity. Since pottery easily absorbs moisture, leaving it wet can cause mold.
Avoid sudden temperature changes—do not wash hot vessels in cold water or place hot dishes directly from the refrigerator into it.
The Joy of Development
It is said that pottery becomes more flavorful with use. Koizago ware also develops increased color and luster as oil from use penetrates the clay. Enjoying this change is one of the pleasures of using pottery.
The brilliance of gold crystals also changes to soft luster with continued use. Experience the joy of developing your own vessel.
Conclusion
Koizago ware is a traditional ceramic with over 190 years of history produced in the Koizago district of Nakagawa Town, Tochigi Prefecture. Beginning with Tokugawa Nariaki, daimyo of Mito Domain, discovering the ceramic clay, it developed under the domain’s industry promotion policy.
Unique colors such as the golden-gleaming “gold crystal glaze” and peach-colored “copper red glaze,” and the intermediate character between pottery and porcelain resulting from clay abundant in kaolin, are major characteristics of Koizago ware. Its rustic yet refined colors are loved from everyday dining tables to the world of tea ceremony.
Currently, several kilns continue tradition while undertaking pottery making suited to contemporary life. While challenges such as successor development and information dissemination exist, recognized as a cultural heritage of the Koizago district, designated a “Japan’s Most Beautiful Village,” its value is being re-recognized.
Koizago ware vessels are not merely daily goods but artworks embodying Tochigi Prefecture’s history and culture and the techniques of artisans. Why not visit a kiln and directly experience its appeal? Koizago ware vessels, which increase in attachment with use, will surely enrich your life.
