Variations: Raijū, Thunder-animal, Thunder-beast
In Japan, it is said that lightning cannot pass through a mosquito-net – and neither can the Raiju. These creatures also hate the smell of incense.
A raiju, or thunder-beast, ranges from dog to squirrel in general appearance, but usually resembles a badger. It falls from the sky with the lightning, and jumps from tree to tree. After the storm has passed, evidence of the raiju’s presence can be seen in the torn, deeply gouged treetrunks and woodwork where a raiju dug its claws in. Such raiju-damaged trees can be harvested for bark that cures toothache.
Raijus will pounce on anyone taking shelter beneath a tree, and will enter any house unprotected by mosquito netting or incense. They also love to eat human navels, and so it is vital to keep one’s navel protected during a thunderstorm, sleeping face-down if necessary.
Despite their elusive nature, raijus have been captured on multiple occasions. The Edo period in particular has many such cases across Japan, and it is believed the Chinese Bencao gangmu text was the inspiration for the raiju craze. One raiju got tangled in the ropes of a well and was taken alive. Another raiju was exhibited (for a fee) in a brass cage in the Temple of Tenjin in Matsue. It looked like a badger, and was said to sleep during fair weather, but during storms it would become active, with its eyes flashing.
The masked palm civet or hakubishin (Paguma larvata) is the most likely contender for the originator of the raiju. This badger-like animal was brought over to Japan from mainland Asia perhaps as early as the Edo period, its unfamiliar nature leading to tales of lightning beasts.
Foster, M. D. (2015) The Book of Yokai. University of California Press, Berkeley.
Hearn, L. (1910) Glimpses of Unfamiliar Japan (Second Series). Bernhard Tauchnitz, Leipzig.