The Tanaka Shozo Memorial Museum is a history museum located in Ote-machi, Tatebayashi City, Gunma Prefecture. Its official name is the “Ashio Copper Mine Pollution Incident Tanaka Shozo Memorial Museum.” The museum was established to preserve the history of the Ashio Copper Mine Pollution Incident, regarded as one of Japan’s earliest major environmental pollution problems, and to introduce the life and activities of politician Tanaka Shozo, who worked to seek relief for those affected.
Through photographs, historical documents, videos, and other materials, the museum introduces the reality of the mining pollution that occurred during the Meiji period, the lives of people who suffered from its effects, and Tanaka Shozo’s efforts to address the problem.
The museum offers an opportunity not only for history enthusiasts but also for visitors interested in Japan’s environmental history, social movements, and the relationship between industrial development and people’s lives.
The Ashio Copper Mine Pollution Incident is regarded as one of the first large-scale environmental pollution problems in Japan. It occurred mainly during the late Meiji period in connection with the Ashio Copper Mine in western Tochigi Prefecture.
At the time, Ashio was one of Japan’s largest copper mines and accounted for approximately 40 percent of the country’s copper production. At the same time, mining and smelting generated pollutants that had serious effects on surrounding forests, rivers, farmland, and local communities.
Smoke produced during copper smelting contained substances such as sulfur dioxide, causing extensive damage including the decline of surrounding forests. Water and waste rock flowing from the mine also contained heavy metals such as copper, lead, zinc, arsenic, and cadmium.
These pollutants entered the Watarase River, affecting river water and agricultural soil throughout the watershed.
The Watarase River had once been known for its exceptionally clear water and supported abundant fish and agriculture along its banks. As pollution spread, however, fish populations declined and crops were damaged, causing serious problems for agriculture and everyday life.
When floods occurred, pollutants were carried farther downstream. The resulting damage therefore extended beyond Tochigi Prefecture into areas including Gunma and Saitama prefectures.
As the pollution became increasingly serious, farmers living along the Watarase River organized to protect their livelihoods. They repeatedly petitioned and protested to the government and the mining authorities, demanding compensation for damages and measures to halt or control the mine’s operations.
At the time, large groups of affected farmers traveled to Tokyo to make their demands directly to the government. These collective actions became known as “Oshidashi” and developed into a major social movement.
One of the central figures in this movement was Tanaka Shozo, a politician from Tochigi Prefecture.
Tanaka Shozo (1841–1913) was a politician active during the final years of the Edo period and throughout the Meiji period. He was born in Konaka Village in present-day Sano City, Tochigi Prefecture. From an early age, he took an interest in problems affecting local communities and became involved in the Freedom and People’s Rights Movement.
After being elected in Japan’s first House of Representatives general election in 1890, Tanaka raised the Ashio mining pollution issue in the National Diet. He urged the government to recognize the severity of the damage and the difficult circumstances faced by affected farmers.
In 1891, he personally investigated the affected areas and reported the seriousness of the pollution to the National Diet. He continued to demand government action and measures to protect the affected communities.
In 1901, Tanaka resigned from the National Diet and attempted to make a direct appeal to Emperor Meiji on behalf of people suffering from the pollution. The appeal was stopped by security officials, but the incident attracted considerable public attention and became one of the events that brought the Ashio pollution problem to wider national awareness.
Tanaka continued working alongside affected residents and eventually lived in Yanaka Village in the Watarase River basin while seeking a solution to the problem. He remained active until his later years and died in 1913 at the age of 71.
The museum presents a variety of materials that help visitors understand the development of the Ashio Copper Mine Pollution Incident and Tanaka Shozo’s activities. Photographs, explanatory panels, videos, and other resources are combined to make this complex chapter of history easier to understand.
Approximately 500 historical items are displayed, including out-of-print reference books and records from the period.
The museum also exhibits handwritten letters by Tanaka Shozo addressed to people connected with the issue. These materials offer clues to the thoughts and concerns of those who confronted the pollution problem at the time.
In addition, approximately 1,500 books, including donated materials, have been cataloged in the museum’s collection. These materials can be viewed by prior arrangement, although they cannot be removed from the museum.
Exhibition panels use historical photographs and records to explain the development of the Ashio Copper Mine Pollution Incident. Visitors can see valuable photographs documenting the affected areas during the Meiji period and the farmers’ movement for relief.
The museum also uses an educational video titled “The Ashio Copper Mine Pollution Incident Today”, along with traditional-style picture storytelling materials, to make the historical events more accessible and engaging.
A handmade diorama in the museum’s rear garden illustrates the overall geographical scope of the Ashio pollution incident.
The terrain of the Watarase River basin and the areas affected by pollution are represented three-dimensionally, helping visitors visualize how far the effects spread. The model provides a particularly clear way to understand the geographical scale of the incident, which can be difficult to grasp from written records and photographs alone.
The Tanaka Shozo Memorial Museum was also established through the efforts of local citizens.
In 1998, the Memorial Museum Construction Promotion Association was formed, leading to signature campaigns and efforts to encourage government support. The museum eventually opened on October 1, 2006, after an unused room in a former Wataze Nursery School building in Ashitsugi-cho, Tatebayashi, was renovated for use as the museum.
The original facility was relatively small, with an area of approximately 40 square meters. As visitor numbers and the collection of historical materials increased, the space became insufficient. On November 4, 2013, the museum moved to its current location in central Tatebayashi. The new facility is approximately four times larger, allowing for more extensive exhibitions.
The Tanaka Shozo Memorial Museum is located in the “Historic Path” district in central Tatebayashi. Historic temples, cultural sites, and other landmarks are scattered throughout the surrounding area, making it possible to combine a museum visit with a walking tour of the former castle town.
The museum also hosts special exhibitions on the Ashio Copper Mine Pollution Incident and Tanaka Shozo. These exhibitions provide opportunities to explore different aspects of the history and discover new research and perspectives related to the subject.
The Tanaka Shozo Memorial Museum is approximately a 15-minute walk from Tatebayashi Station on the Tobu Isesaki Line. Located in central Tatebayashi, it is convenient to visit together with other attractions in the city.
The Tanaka Shozo Memorial Museum preserves the history of the Ashio Copper Mine Pollution Incident, the experiences of the people affected by the pollution, and the efforts of Tanaka Shozo, who worked to seek relief and solutions.
Through its historical materials, visitors can learn not only about modern Japanese history but also about environmental pollution, social movements, and the challenges created by industrial development.
The museum is a valuable educational destination for anyone interested in the history of Tatebayashi, modern Japan, or environmental issues. Combined with a walk through the surrounding Historic Path district, a visit offers a deeper understanding of Tatebayashi’s history and culture.