While walking a mountain trail at dusk or stepping into a dimly lit old house, people often feel something in the air, in the lengthening shadows, on the back of their necks--something absent in a city apartment building.

In ancient Japan, that uncanny "something" was thought to be "yokai," ghouls and hobgoblins lurking in dark and hidden places.

In this bright age of digital technology, we now have a "Dr. Yokai" who gives serious thought to these folklore creatures.

He is Masanobu Kagawa, the chief curator at the Hyogo Prefectural Museum of History, and the first Japanese to get his doctorate in the study of yokai.

In an interview with The Asahi Shimbun, Kagawa said their nonexistent existence is an essential characteristic of yokai.

He also said artificial intelligences that present themselves as human are a modern form of yokai. What makes them scary is that you can't tell them apart from humans, he added.

Excerpts of the interview follow:

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Question: I heard that you research yokai.

Kagawa: My research is not about whether yokai are real or not, but about the essential role that yokai play in human cultures, although it is often difficult for people to understand my stance.

Yokai are fantasies and what makes them yokai is that they don't exist. If they existed, they’d just be rare animals, do you see?

There are unexplained phenomena that happen sometimes in this world. We humans can't stand chaotic situations that don't make sense to us. So, we provide our own explanations by saying it was the work of yokai and feel relieved, at least temporarily.

Q: Could you give an example?

A: When you yell "yahoo" on a mountain, you hear "yahoo" echoed back. In olden times, people explained that spirits called “kodama” or “yamabiko” would mimic human voices and call out to us.

GODS AND MONSTERS

Q: Are yokai similar to "yaoyorozu no kami," or the Japanese idea that there are gods in all things that cause natural phenomena?

A: I think they retain the characteristics of ancient gods. Gods were terrifying to humans, so were yokai. Yokai were not meant to be destroyed, but to be served with offerings and prayers to beg them not to bring curses.

But in the West, there are many stories about saints slaying monsters. They are subjects to be conquered, so to speak.

Q: What are the differences between Dracula and yokai?

A: Well, Dracula is a literary character created by author Bram Stoker, but vampires are closer in essence to Japanese yokai because they are from East European folklore.

Yokai change their forms in line with the times. During the Heian Period (794-1185), "oni" demons (with horns and fangs) represented what we now call viruses. People called things that were invisible to the eye and brought contagious diseases oni.

Q: How about "tengu" (bird-like goblins with wings and beaks)?

A: In ancient times, tengu referred to shooting stars. But they became foxes in the Heian Period for no apparent reason, black kites in medieval times and long-nosed tengu goblins in the Edo Period (1603-1867).

Q: "Kappa" river imps are also famous.

A: You may think kappa are green in color, but that is because ukiyo-e artists in the Edo Period happened to draw them in green, while folklore has it that they are "red" in color.

Q: Come to think of it, Pokemon also sound like yokai.

A: There are scrolls very similar to the Pokemon Encyclopedia dating back to the Edo Period.

Known as "Bakemono Zukushi" (Collection of monsters), these picture scrolls were a type of yokai encyclopedia illustrated with many yokai varieties to entertain children. Yokai were depicted as comical characters in the Edo Period.

WHERE YOKAI DWELL IN MODERN TIMES

Q: If we can find yokai in modern times, what are they?

A: With the modern world becoming increasingly urbanized, we have fewer and fewer environments where yokai can dwell.

If there are yokai now, I think they are found in the internet. After all, they occupy the world of ideas, of information. As our means of communication continues to change from spoken words to printed text and to the internet, yokai also change their forms.

Yokai don't exist for real, so they can only live in the world of media. That's because they are merely information.

Q: So, they live in the internet now?

A: Exactly. It is like dealing with yokai when we are suddenly smeared by people we don't even know. I think the internet is quite like the world of yokai.

In olden times, yokai were born from rumors. It took time for them to change because they traveled by word of mouth. However, it was impossible to know the original source, so they had a wide scope of variations.

Meanwhile, you can use the internet to track down the original source of a rumor, but it changes at a faster speed.

Q: How do you think yokai will change from now on?

A: Artificial intelligence has changed the landscape.

If we are on the internet, there is a high probability that we are interacting with ordinary people. But AI is definitely not human.

ChatGPT, a generative AI service, is quite similar to yokai, isn't it? It acts like a human and gives responses like those prepared by humans.

It is disguised as a person but actually--it is not human at all. And you can't tell the difference. Don't you find that scary?