Kazuya’s parents passed away due to illness when he was small and he and his imouto Minatsu were taken in by his father’s acquaintance and they now live in the rural town of Sadogashima. His heart aches when he is lonely and he often goes to a pond in the forest to cry, while clutching a momento from his mother, “tears of a firefly”.
One night, he saved a firefly that was ensnared by a spider’s web. The next day at the pond, a girl suddenly appeared and they watched the fireflies together. As they spent more days playing together, he began to feel happier as he watched her always have a smile on her face. Then one day when he asked her to play together again, she turned downcast and said that she couldn’t. He intended to give the “tears of a firefly” to her as a present, but she never showed up at the pond after that day.
Time passed and he had gotten used to living in the town. In the beginning of summer, a girl named Mikoto transferred into his 2nd-year class. All the guys were excited at having such a pretty girl join their class, but Kazuya was the most surprised… because she was the girl that he had met at the firefly pond.