Hanaoka Incident Site & Peace Memorial Museum

The Hanaoka Incident Site and Peace Memorial Museum in Odate City, Akita Prefecture, commemorates one of the most notorious forced labor atrocities of World War II in Japan. Beginning in August 1944, 986 Chinese laborers were forcibly brought under Japanese government policy to the Hanaoka Mine — operated by Fujita-gumi (later Dowa Mining) — where the contractor Kajima-gumi (now Kajima Corporation) put them to work diverting the Hanaoka River.

The Chinese workers endured inhumane conditions including severe physical abuse by overseers, starvation-level food rations, and grueling manual labor. By mid-1945, the death toll from abuse, malnutrition, and disease had become catastrophic. On June 30, 1945, the surviving laborers staged a desperate uprising, during which four Japanese supervisors and one Chinese collaborator were killed. The subsequent crackdown was brutal — more than 100 Chinese workers were killed in the three days after the uprising, and survivors were subjected to further torture. By December 1945, a total of 418 out of the 986 laborers had perished, a mortality rate far exceeding that of other forced labor camps in Japan.

After the war, American occupation authorities investigated the incident. On March 1, 1948, a U.S. Eighth Army tribunal at Yokohama convicted six men — four Kajima staff and two police officers — of Class B and C war crimes: three were sentenced to death (later commuted), two to life imprisonment, and one to 20 years; all had been released by 1955. In October 1949, Kajima constructed a memorial at a local Buddhist temple, and the remains of the victims were repatriated to China between 1953 and 1964. A landmark lawsuit filed in 1995 resulted in a settlement of 500 million yen ($4.3 million) by Kajima Corporation in 2000.

The Hanaoka Peace Memorial Museum (花岡平和記念館) was completed in September 2009 and opened to the public in April 2010 in the Hanaoka-cho Maeda district. It was the first memorial museum in Japan built at a site of wartime atrocity through citizen-led initiative. The museum houses permanent exhibits documenting the forced labor program, the uprising, and its aftermath, and had received some 8,000 visitors from Japan and abroad as of 2019.

Every year on June 30, a memorial ceremony hosted by Odate City is held at Toseno Park Cemetery, attended by Chinese survivors' families, representatives from the Chinese Embassy, and local citizens, ensuring that this chapter of wartime history is not forgotten.