All sorts of strange creatures and weird monsters populate the folklore of Japan. Known by a variety of terms, including bakemono, obake, and most common today, yōkai, they are associated with myth, folktale, and local legend. But they are also found in all sorts of dramatic, literary and artistic works, and more recently in movies, manga, anime and video games. In fact, these days Japanese monsters don’t live exclusively in Japan: lucrative franchises such as Pokemon and Yo-Kai Watch draw on many of the monsters of the folk pantheon—and with the explosive popularity of Pokemon Go, Japanese monsters can be captured in the U.S. and everywhere else.

The notion of yōkai is broader than the English-language monster or spirit. It can indicate ineffable phenomena, such as creepy sounds in the night or fireballs flitting around a graveyard, but it can also refer to mischievous or demonic creatures living in the mountains or the ocean, or even to real animals—such as foxes and tanuki raccoon dogs—that were said to have the ability to shift their shape. Some yōkai are humanlike in form, and others look like sprites or weird beings, akin to the manifold creatures of European fairylore. And with regard to behavior, too, the monsters of Japanese lore run the gamut from mischievous and even murderous, to benign and sometimes protective.

An example of this variety embodied even in a single yōkai is the zashiki-warashi in the current exhibition. A small, childlike spirit, the zashiki-warashi inhabits a house unseen, causing all sorts of minor mischief, like flipping over pillows, spilling things and shifting furniture around. Despite its troublemaking behavior, having one of these invisible familiars lurking about is considered a sign of good fortune for the household. On the other hand, if one day you happen to catch a glimpse of your resident zashiki-warashi, this may be a sign that it will soon depart for another home, and your family fortunes will soon decline.

But why are there yōkai in the first place? In one sense, perhaps, it is a way for humans to seek causality and agency in the natural world. We can think of the creation of yōkai as an inventive way of interpreting or explaining the otherwise mysterious things we observe around us. When you hear strange sounds at night, for example, it is not difficult to imagine that some sort of creature or spirit—ghostly or otherwise—is making them. Or when a tree falls in the woods for no apparent reason, it is not unreasonable to imagine it was felled for some purpose by an invisible force.

Often, it is with the attribution of a specific name that an invisible force or strange phenomenon comes to life as a creature with a body and will of its own. Take the azuki-arai, featured in the current exhibition. It is likely that this creature is based on a sound: to some imaginative individuals long ago, the burbling of water over stones in a brook sounded like a person washing dried adzuki (azuki) beans, and thus, the azuki-arai, or “bean washer,” was born. And with the name, an appropriate image also comes into focus: in this case, a somewhat crazed and awkward figure of a man obsessed with scrubbing and counting beans.

Sometimes a mysterious creature may be born of nothing more than a feeling. There is, for example, a yōkai called mokumokuren, portrayed as a shōji screen or the wall or a house with dozens of eyes. Of course, nobody knows how such an image came about, but we can certainly imagine somebody spending the night alone in an abandoned house in the forest, and having the creepy feeling that they were being watched. The mokumokuren becomes the architectural embodiment of this feeling—and perhaps a perfect metaphor for a surveillance society!

At the heart of the yōkai idea is the concept that any object might possess an animating spirit. Such an animistic worldview has traditionally informed Japanese religious concepts that suggest that all sorts of things—including trees, stones, mountains and other natural features—can be inhabited by deities or kami-sama. Not surprisingly, many a yōkai walks a razor’s edge between the monstrous and the godly. Take the kappa (literally, “river-child”), an exceedingly common water sprite, found in legends throughout Japan, that looks a bit like a giant turtle or frog. These playful and impish creatures enjoy challenging passersby to sumo wrestling, but they can also be vicious and deadly, notorious for drowning small children and livestock—a pretty effective warning for kids to stay away from the water! At the same time, a kappa might be worshipped as a powerful and protective water deity, perhaps appeased with an offering of a cucumber, one of its favorite foods (hence the “kappa roll” famous at sushi shops!). In some farming communities there were traditions whereby the kappa—after living in the river and irrigating the rice fields all summer—was ceremoniously sent off to the mountains at the end of harvest. There it would transform into another fantastic being, known as the yamawarō, or child of the mountains.

Almost as long as yōkai have been part of folk culture, they have also been part of artistic, dramatic, popular and commercial culture. During the Edo period (c.1600-1868), for example, they were a common theme of woodblock prints as well as popular illustrated literary texts, the precursor of today’s manga. They were also found in monstrous catalogs, board games, and card games, where they often came to be portrayed as more cute or comical than creepy. In one sense, games such as Pokemon and Yo-kai Watch build on this older, traditional realm not just for content but also for form, suggesting an encyclopedic mode in which people collect, catalogue and play with the creatures of the otherworld.

Despite the fact that they have been around for centuries, however, yōkai always reflect a spirit of imagination, inventiveness and change. In Japan today, many towns and villages have mascot characters, known as yuru-kyara. Sometimes these take the form of a specific yōkai, based directly on old legends from the region. In many cases, however, village leaders fashion unique yuru-kyara by combining local characteristics—a particular landscape feature here, a famous product there—into a made-up being that can be used as a memorable icon or mascot to reflect community identity and distinctiveness. In a way, this creation of a local representative creature is a conscious version of the same processes that went into the imagining of more traditional yōkai. Like yuru-kyrara, yōkai are abundant and varied and always changing to meet contemporary needs and interests, reflecting the richness of human imagination.