One warm, wet July evening, amateur photographer Tsuneaki Hiramatsu picked his way through a forested shrine in the northwest region of Japan’s Okayama Prefecture. A sudden thunderclap startled him, but he pressed on. It would soon be the magic hour. As the sky lost its luster and silence descended upon the forest, fireflies began to emerge, one by one, eventually enveloping Hiramatsu in light. “It was as if I’d stepped into a different world,” he writes in an email translated from Japanese. “Emotion began to swell in me from the bottom of my heart, and I felt as if all the collective memories of humanity had been awakened in me.” Camera in hand, Hiramatsu snapped hundreds of long-exposure digital photographs while the flickering insects danced around him. Later on, after uploading his files onto a computer, he used a layering tool in Photoshop to combine individual images into the enchanting composite you see here.Hiramatsu has been photographing fireflies—of which...