Hitodama

In Japanese folklore, the souls of the recently deceased take the form of mystical lights. They are also known as onibi (demonic lights").

It is assumed that such lights are pale blue or green spheres with long tails. It is usually said that hitodama appears in summer, near cemeteries, gloomy forests or next to a dying person, as a manifestation of the soul leaving the body (although some say that they saw these lights just before the birth of a child).

Most of the hitodams go out or fall to the ground shortly after people notice them, although it is believed that they lead travelers off the right path and make them get lost.

Perhaps they were mistaken for these fluorescent gas, which sometimes appeared over the graves.