The title Hotaru means firefly. This story was written more than one thousand years ago, during the time when there was no electricity; the only possible light at night came from oil lamps or candles.

In this scene from the novel, a male character is making a night visit to the lady Tamakazura. This had been 'arranged' through a long exchange of poems and letters between the two. But unknown to either of them, Genji (the main character of the novel) was present, hidden in the darkness.

He suddenly released into the room a group of fireflies which he had prepared beforehand, surprising both of them, and leaving her in great embarrassment at being seen by her guest. (Noblewomen in those days didn't show themselves to other men.)