We conducted a field survey and a workshop for an environmental investigation aimed at the restoration of fireflies in a suburban area of Higashi-Hiroshima City, Japan. We investigated distributions of fireflies in cooperation with interested persons in the area. A map showing the firefly distribution, prepared at the workshop, exhibited that Luciola crusiata and Luciola lateralis were observed at 13 sites in the study site during July 2009. Thereafter, we also investigated environmental conditions at each site. Environmental conditions including water quality and physical factors at each site were similar to those described in reports of previous studies. Results of our study clarified that habitats required by fireflies are preserved at the study site, although most area residents have a negative image of regional environmental conditions.