Hotaru (fireflies) are one of nature's smaller, yet sublime occurrences. The tiny, 15-mm-long bugs live only two weeks after hatching, but are blessed with phosphorescent rear ends which make clusters of them a captivating sight on summer nights. Their almost-fluorescent glow also ensures the continuation of the species: During their short life span fireflies use that glow to court before mating, subsequently hatching eggs and then dying a few days later.

The bugs have long been considered a symbol of this season, and appear in countless poems extolling the simple pleasures of rural summertime. Early each June, firefly-watching events are held around Japan. These can be magical experiences: intimate quartets, for example, held in quiet forests and known to only a handful of people. Unfortunately, many events have a more adverse effect. Noisy crowds that arrive with glaring lamps and car stereos, leaving behind garbage and trampled riverbanks, frighten away every last firefly in the area.

Fireflies are found in verdant, unspoiled countryside with clean rivers, far from the bright lights and refuse of human settlements. After mating, eggs are deposited into these rivers, where they hatch into larvae and grow. The larvae crawl out of the river the following April, develop into chrysalides and then sprout wings in June, before beginning the mating process anew. Females are slightly larger than males and their glow is more intense, but they are fewer in number. They tend to fly lower, near preferred hatching zones such as moss and deep grass.