After Meiji Restoration, Japan endeavored to modernize herself and promote industrialization. However, such ambition was hampered by the lack of technicians. To make up for such deficiency, Koshu Gakko, an institute that provided technical training was founded under the collaboration of the imperial government and private enterprises. The success of Koshu Gakko in cultivating technicians not only contributed to the domestic industrialization and modernization of Japan, these technicians also played a role in the imperial expansion of Japan to its neighbors including Taiwan, Korea and Manchuria. This study traced the source of architectural technicians in Japanese colonial Taiwan, and examined the roles and importance of graduates from Koshu Gakko in the Department of Building and Repairs of Taiwan Sōtoku as well as their interaction with technicians trained by the Tokyo Imperial University and other technical institutes. This exploration served to highlight the relationship between flow of technical talents and colonial governance. The case study of Otsuzi Kuniyosi, a graduate of Koshu Gakko, portrayed the actual life of an architectural technician in the Japanese colonial government and the historical significance he represented.