In this paper, we found a flower garden in the vacant lot in the historical urban area contributed to revitalizing the local inhabitants’ social interactions and made their relationship strong enough to support their neighbors. A part of the vacant lot was borrowed for free and changed into a flower garden by the neighbors. We thought that this situation was caused by the characteristic the vacant lot. The feature of this study is to consider the abovementioned phenomenon by the observational research for over 30 days at a garden that has been being maintained by the neighbors in Yame Fukusima.