Kijimuna

A framing note first: this is Ryukyuan, not Japanese. Okinawa had its own kingdom, its own language, and its own cosmology, and the kijimuna belongs to that tradition rather than to the mainland yokai canon. It's told here as Okinawa's.

The children in the banyan

In the aerial roots of the gajumaru — the Okinawan banyan, which drops curtains of root from its branches and makes cavernous hollow spaces — live small children with wild red hair.

They are three or four years old, and they always will be. The name glosses as "child of the tree."

They love fishing. They are extremely good at it.

And they eat only the left eye of every fish they catch.

That's the detail everyone remembers, and it's the most specific table manners in world folklore. A kijimuna will land an enormous catch, take one eye from each fish, and leave the rest.

Which means the evidence is checkable: find your fish missing an eye, and a kijimuna was working your cove.

They'll befriend you, and it will end badly

Kijimuna make friends with human fishermen. They ride in boats. They share catches — and a fisherman with a kijimuna partner does very well, because the kijimuna knows where the fish are.

And the friendships reliably fall apart. The recorded triggers are a wonderful mix of the grave and the ridiculous.

Cut or burn its banyan and you've earned a lifelong grudge. That one is serious and it's the core of the relationship: the tree is the being.

Bring octopus near it. They cannot stand octopus.

They also dislike chickens, and — inexplicably and marvellously — hot pot lids.

And then the greatest entry on any countermeasure list in this collection:

Do not pass gas while riding on its back.

That will end the friendship permanently. I have nothing to add.

The chest-sitter

There's a serious clause too. The kijimuna sits on sleepers' chests and paralyses them.

That's Okinawa's answer to sleep paralysis — the experience the mainland assigns to other culprits and which the whole world has independently populated with something heavy that sits on you. Every tradition that has the experience gives it a tenant, and this one is a red-haired child from the tree outside.

The fires, on a date

And a proper eerie note to finish.

On the tenth day of the eighth lunar month, the kijimuna-bi — kijimuna fires — appeared, and people turned out to watch them. A public spectacle, scheduled.

But a kijimuna-fire that rose was a death omen.

So you have a community gathering on a known night to look at supernatural lights, in a mood somewhere between festival and vigil, watching to see if any of them go up.

They're still beloved. There is a Kijimuna Festa in Okinawa, and statues of them — under their other name, bunagaya, "big-head" — in Ōgimi.

A creature that steals fish eyes, hates hot pot lids, paralyses sleepers, and has a festival named after it.