The numbers don’t lie: When it comes to spending money on Halloween, the Japanese have nothing on Americans; consumers in the United States shell out $6.9 billion during the holiday, compared with ¥122 billion, or about $1 billion, in Japan. But the country that popularized costumed performance art like kabuki and cosplay does have a competitive edge in one realm: Perhaps no country loves—and hates, and fears, and imagines—monsters to the extent that Japan does.

In Japan, monsters—or really any otherworldly or inexplicable being—are known as yōkai. One of the first compilations of yōkai, the 18th-century Konjaku Gazu Zoku Hyakki (“Continued Illustrations of the Many Demons Past and Present”), contained 54 entries. Wikipedia lists almost 300 “legendary creatures from Japan,” including kamaitachi (a “slashing sickle-clawed weasel that haunts the mountains”), gashadokuro (“a giant skeleton that is the spirit of the unburied dead”), and tsurube-otoshi (“a monster that drops out of the tops of trees”). Yōkai have inspired at least two Internet databases.

According to Michael Dylan Foster, a scholar of Japanese folklore at Indiana University Bloomington, the origins of yōkai are diverse. Some yōkai aren’t strictly Japanese, but rather derivatives of Chinese legends or characters from Buddhist texts (like the oni, giant demons similar to ogres). Many first appeared in local tales and were incorporated into folklore when oral storytelling (setsuwa in Japan) was committed to writing. Like most folklore around the world, the yōkai reflected concerns in Japanese society—like fear of outsiders and the ambiguity of death—at the time they were conceived. There was the concept of the hyakki yagyō, or “night processional of 100 demons” invading the real world, and tales of yūrei, ghosts who’d failed to pass on and were prone to taking revenge on the living. Consider the story of the weeping stone, recounted in Ghost and the Japanese: Cultural Experience in Japanese Death Legends:

Along the path through the mountains near Sayo-no-Nakayama on Honshu, there is a stone that you can hear crying and complaining. A long time ago, people found a pregnant woman traveler dead and robbed on that spot. The murderer was never caught, and so the killing remains unresolved and unatoned for. The unlucky spirit of the dead woman could never find any rest, and finally took refuge in that stone. Every night she weeps because of her grief. You can still hear her crying.

Foster, writing to me by email (he was in Japan attending a symposium about yōkai), said the large number of yōkai in Japan doesn’t have “anything to do with there being more belief in the supernatural or in folkloric creatures in Japan than there is elsewhere.” Instead, he added, “it has to do with the way in which yōkai, at a fairly early stage, became a very lively part of popular culture (fiction, drama, illustrated texts, games, etc.).”

This integration into pop culture dates back to the Edo period of Japanese history between the 17th and 19th centuries. In Pandemonium and Parade: Japanese Monsters and the Culture of Yokai, Foster describes how chronicling the exploits of yōkai became a form of recreation, in part through telling ghost stories in an event called hyaku-monogatari, or “100 stories.” The storytellers would light 100 lanterns and extinguish one for each tale told, until their surroundings gave way to total darkness. At this point, a yōkai would supposedly appear among those in attendance.