Although there were many habitats of fireflies in Japan in the Edo-era, they dramatically decreased in these 100 years because of river pollution. However, the Niizaki-river and the Chitose-river are the exceptions.
In Yugawara, the tourist association holds "Firefly Festa" at the Manyo-koen park in early part of June. This is a flag advertising the Festa at the JR station. We can visit the Manyo-koen park from here by bus.
Please click on the photos.