Manmo Pioneer Peace Memorial Museum

The Manmo Pioneer Peace Memorial Museum (満蒙開拓平和記念館) opened in April 2013 in Achi Village, a mountain community of approximately 6,300 residents in the Shimoina District of southern Nagano Prefecture. It is the only museum in Japan entirely dedicated to the history of the Manchurian-Mongolian colonization program (満蒙開拓), which between 1932 and 1945 dispatched roughly 270,000 Japanese agricultural emigrants to the puppet state of Manchukuo in northeastern China.

Nagano Prefecture bore a disproportionate share of this emigration: approximately 33,000 residents — more than any other prefecture — left for Manchuria, with the Iida and Shimoina districts contributing the most. The Great Depression had devastated the region's silk-farming economy, and local politicians and educators actively promoted emigration as salvation. Around 800 emigrant groups were formed, including the seishōnen giyūgun (youth pioneering brigades) composed of boys as young as 14 or 15.

When the Soviet Union invaded Manchuria on August 9, 1945, the Kwantung Army — which had promised to protect the settlers — retreated without warning, leaving roughly 223,000 mostly elderly, women, and children defenseless across the vast Manchurian plains. In the ensuing chaos, an estimated 80,000 settlers perished from combat, starvation, disease, attacks by local populations whose lands had been confiscated, and waves of mass suicide (shūdan jiketsu) born of despair. Thousands of Japanese children were orphaned and adopted by Chinese families, becoming the 'war-displaced orphans' (zanryū koji) whose search for their Japanese identities would continue for decades.

The museum project was formally adopted in July 2006 by the Iida Japan–China Friendship Association, with former emigrants acting as 'storytellers' to pass on their experiences. The facility is run by a private organization and relies on admission fees and donations, although part of the construction cost was subsidized by Nagano Prefecture and local governments. The museum's seven exhibition rooms trace the full arc chronologically: pre-war rural hardship and propaganda, the emigration process, life in Manchurian settlements, the Soviet invasion, the harrowing escape attempts, post-war repatriation, and long-term aftermath.

Today the museum coordinates storytelling programs where surviving emigrants share firsthand accounts, hosts seminars on peace education, and holds annual memorial ceremonies each August. Its volunteer organization, Peace Labo, draws members from across Japan who serve as guides and educators, ensuring the lessons of this wartime tragedy are transmitted to future generations.