Regional cities in Japan are facing a decline in the downtown area owing to urban expansion and a decrease in the population. Promoting downtown living is indispensable for the realization of downtown revitalization. Since many coastal cities originally developed outward from a port, their downtown areas are located near the coast and are at high risk of tsunamis. The purpose of this research is to reveal the effectiveness of dealing with the above two issues in parallel by evaluating the Deae-ru Saiwai estate, a public housing relocation project in downtown Kushiro, Hokkaido, Japan that incorporates a tsunami evacuation facility with questionnaires and a GIS survey. Placing public housing in the downtown area shortens the distance to public facilities and improves the convenience of the surrounding environment for many residents. Installing the tsunami evacuation facility improves the feeling of reassurance of residents who would feel anxiety about immigration with regards to tsunamis. This research has clarified the synergistic effect of dealing with the daily and emergency issues in parallel for promoting downtown living. Planning downtown revitalization and disaster prevention concurrently, which has been separated so far, is a fundamental planning approach for urban revitalization in regional coastal cities.