Kamiunai Farm 21 Plant Factory stands as a remarkable example of agricultural architecture completed in 2001. Located in Uraushi Town, Hokkaido, this facility was designed by Tasei Construction and represents an innovative approach to controlled environment agriculture. The plant factory represents the integration of advanced horticultural technology with architectural design, showcasing how modern structures can optimize crop production through precise environmental control. As a forestry and fisheries facility, it exemplifies the evolution of agricultural buildings in Japan during the early twenty-first century, merging sustainability principles with efficient spatial planning. This structure remains significant for architects studying the intersection of agriculture and contemporary building design.