The persistent low birthrate and aging of society has resulted in changes to the demographic structure and low economic growth, increasing the number of vacant houses and stores. This causes, in turn, various social problems such as high crime, a deteriorating landscape, and low- quality residential environments. To solve these problems, the central and local governments have begun to consider vacant space to be an important policy subject. Here, we propose the concept of “tactical utilization,” investigate major issues with implementing this concept, and suggest a system for activating this type of vacant urban space utilization.