Hyakumonogatari Kaidankai

This is where a very large amount of Japanese folklore actually comes from — not a village, not a shrine, but a party game.

The rules

A room. A hundred lit wicks, usually behind blue paper lantern screens, which throws everything into a cold underwater light.

A circle of people. One tells a ghost story. When it's finished, they go and put out one light.

Then the next person tells one, and another light goes out.

The room darkens by one increment per story, arithmetically, all night. And the tradition holds that when the hundredth light is snuffed and the room goes fully black, something arrives.

It began as a samurai courage test. Sitting in the dark listening to the dead being discussed was a way of proving your nerve, which is a very martial-class approach to an evening in.

The first recorded punchline is a spider

The earliest version we have of what happens at a hundred is not terrifying. It's almost a joke, and it's better for it.

In Ogita Ansei's Tonoigusa, at the hundredth tale, a great hand comes down from the ceiling.

Somebody slashes at it with a sword.

And it turns out to be the leg of a spider — about three inches long.

The summoned horror, measured, is three inches of arachnid. That's the tone the whole practice started in: half genuine dread, half a room full of young men daring each other and then finding the actual monster underwhelming.

The version engineered to produce hauntings

The elaborate form, from the Edo manuals, is the one I find genuinely clever — because it isn't a game any more, it's an apparatus.

You use three rooms.

The tellers sit in the first. The far room holds the ninety-nine remaining lamps and a small mirror. And between them is an empty, dark room.

After telling your story, you walk alone — through the dark room — to the far room. You put out one lamp. And before you come back, you look into the mirror.

Then you walk back through the dark.

Do that ninety-nine times, in a circle of people, over a night, with the light falling steadily and your own face waiting in the glass at every trip.

Nobody in that room needs a ghost. The game is a machine for manufacturing them, and the people who designed it knew exactly what they were building.

They stopped at ninety-nine

Standard practice was to leave the game incomplete.

Not out of fear, exactly — out of the sense that finishing the count would be daring something, and nobody wanted to be the one who insisted on it at four in the morning.

That's what the blue-lantern woman with the horns is: the personified thing waiting at a hundred that nobody quite wanted to check on.

Why Japanese ghosts belong to summer

Two reasons, and the second is delightful.

Obon falls in August — the festival when the dead return to visit the living. The season is already thick with them.

And there was a folk theory that being frightened cools you down. A chill up the spine, in a Japanese August, is not a metaphor; it's relief. Ghost stories were seasonal because horror was understood as air conditioning.

That's why Japanese ghost films still come out in summer, and why the tradition's scariest month is the hottest one.

It became a publishing industry

The game turned into a literature.

Collections started appearing with titles that are literally "a hundred tales" — the game bound as a book, sold to people who needed material for their own gatherings. The most important of them, from 1677, is a recurring source behind entries throughout this collection, and it made a specific claim about its contents:

that every tale in it was true.

So a meaningful share of what survives as Japanese folklore survives because somebody needed ninety-nine stories to get through a summer night, and a printer noticed there was money in it.