Hotaru Minako

Hiroshi went on a trip to visit Hiyose, attracted by its natural beauty and by the taste of the local potato shochu he once drank. On the train, he met a beautiful girl named Minako. She was fighting alone to protect the natural scenery and the fireflies of Hiyose, which were about to be destroyed by the construction of a paper mill. Hiroshi fell in love with Minako, and on the night of the summer festival, he witnessed a shocking scene.

(Source: Mangapedia, translated)