What Yōkai Are/Aren’t
Yōkai, 妖怪, are strange, supernatural creatures and phenomena from Japanese folklore. The word is a combination of the characters 妖 (yō-attractive, bewitching, calamity) and 怪 (kai-mystery, wonder).
Over the years, many different English words have been used as translations. Yōkai can be translated as monster, demon, spirit, or goblin, but it encompasses all of that and more. The world of yōkai also includes ghosts, gods, transformed humans and animals, spirit possession, urban legends, and other strange phenomena. It is a broad and vague term, and nothing exists in the English language that quite describes it. Yōkai is one of those words-like samurai, geisha, ninja, and sushi-that is best left in its native tongue.
One of the most difficult things to define are the boundaries of what constitutes a yōkai, and what isn’t a yōkai. Even in Japanese, the term is difficult to pin down. Over the many eras of Japan’s history, different words have been used as catch-all terms for the supernatural forces of this world; bakemono, obake, mononoke, kaii, oni. Depending on who you’re talking to, specific creatures may or may not be classified as yokai. Are ghosts yōkai? Are oni yōkai? Can good spirits be yōkai or are they only evil spirits? Are kami yōkai? Does yōkai only apply to Japan, or does it apply to all countries? Every rule has an exception, and every answer has a contradiction.
The broadest possible definition of yōkai includes all supernatural creatures and phenomena from all parts of the world. Essentially, everything supernatural everywhere. I prefer to use a broad brush when defining yōkai, but not that broad. In my books and on this site, yōkai refers to all supernatural creatures and phenomena which are found in Japanese folklore. My definition is limited specifically to Japanese folklore for two reasons: because yōkai is a Japanese word, and because there already is an English word which describes everything supernatural from everywhere-supernatural. But aside from restricting the definition to Japanese folklore, I prefer to define yōkai with as broad a brush as possible.
A Brief History of Yōkai
Japanese folklore is an amalgamation of different traditions, with its foundation in the folk religions of isolated tribes living on the Japanese isles. These traditions were modified by Shintō and later Buddhism, incorporating elements from Chinese and Indian folklore and mythology as well.
The oldest recorded histories of Japan go back to the 8th century and contain the creation myths and legendary prehistory of Japan. Various documents catalog these stories from different perspectives, and contain the earliest records of the gods, demons, and other supernatural creatures of Japanese folklore.
In ancient Japan, spirits were thought to be formless and invisible to the human eye. However, as artistic traditions developed, it became necessary to visually depict the spirits and monsters from stories. These begun as painted scrolls, and later expanded into multi-volume illustrated encyclopedias of strange tales and supernatural stories.
During the Edo period (1603-1868), there was an unprecedented flourishing of culture and art in Japan. Ghost stories and stories about monsters and strange phenomena from the all over Japan experienced a huge surge in popularity. The very first mythical bestiaries were put together by folklorists and artists like Toriyama Sekien, who collected the oral traditions of rural Japan for consumption by the growing urban population (and added a few original monsters into the mix). Sekien’s yōkai encyclopedias set the stage for other artists, and a new tradition was born. It quickly expanded into every aspect of Japanese culture, from fine art to high theater, from aristocratic ghost story-telling parties to low class bawdlery, and so on.
Yōkai fell out of popularity during the Meiji restoration, when Japan rapidly modernized its society and culture. They were all but abandoned as a relic of a superstitious and embarrassing past. After World War II, manga artist Shigeru Mizuki rediscovered their charm and re-introducted them to a modern Japan. His comic series GeGeGe no Kitaro caused a second explosion of interest in the supernatural. Today, the influence of yōkai can again be seen in all aspects of Japanese culture, from manga and anime, to video games, brand labels, and even on Japanese currency.