This study examines the possibility of using the natural environment and geographical features for disaster risk reduction. This is from the viewpoint of ecosystem-based disaster risk reduction (Eco-DRR) in the area, which is assumed one of the areas to be inundated by the tsunami caused by the Nankai Trough earthquake in the future. Questionnaires were distributed to each household in the coastal area in Nankoku City, Kochi prefecture in January 2016. In total, 419 respondents participated in the survey. The results indicated that 70–80% of the residents in the area regarded earthquakes and tsunamis as hazards. On the other hand, respondents living within 300 m of the coastline regarded the ocean as being more hazardous but charming. Furthermore, tsunami evacuation towers were evaluated positively, and the protection of human lives was regarded as a priority when they participated in consensus building. Countermeasures such as self-aid, mutual aid, earthquake-proofing residences and public facilities, and the prevention of furniture overturning were also expected. In addition, long-term perspectives were related to the conscious use of the natural environment and geographical features; thus, this way of thinking is considered important in promoting Eco-DRR in the assumed tsunami inundation area.