Ishinagenjo

May, in the rainy season, in fog, at night, off Nagasaki. You're out night-fishing.

And beside the boat there is the sound of an enormous rock hitting the water — a tremendous crack and splash, close enough that the boat rocks under you.

There's no rock.

Not floating, not sinking, not visible. And when the light comes up, still nothing.

That's the ishinagenjo, recorded around the Nishisonogi district, the waters off Enoshima, and Tosu in Saga.

The unhappened impact

It belongs to a small and very Japanese category: things that happen rather than things that appear.

Its closest relative is the tengu's stone-throwing — rocks that come down out of an empty sky onto a mountain path, striking with force, with nothing above and nothing found afterwards. The ishinagenjo is that, at sea: the same impact from nowhere, the same absent projectile, moved from land to water.

Nothing threatens you. Nothing appears. Something extremely heavy hits the water a few metres away and there is no reason for it, and you are a long way from shore in fog.

The argument inside the word

Here's what makes this small entry worth keeping, and it's a genuinely funny piece of scholarship.

The name ends in a syllable — -jo — that was never written down carefully enough to settle what it means.

The folklorist Sakurada Katsunori reads it as 女: woman. The stone-throwing woman.

The Kōjien — the standard Japanese dictionary, roughly Japan's OED — reads it as 尉: old man. An old man, idly throwing stones into the sea.

One ambiguous syllable, and the being's entire identity — its gender, its age, its whole character — hangs on which kanji you think somebody meant.

And Murakami adds the deflating note: there is no documentary evidence identifying any creature behind the phenomenon at all.

So the position is this. The event is real and attested: fishermen heard something enormous hit the water, repeatedly, in a particular season, in particular places. The thrower is entirely a matter of grammar.

Is it a woman? An old man? Anything?

The whole attribution market of Japanese folklore — the thing that turns one sound by a stream into a badger in one province and an enshrined grandmother in the next — compressed into a single hiragana character that nobody wrote down clearly.

You don't often get to watch the machinery this close up. Usually the invention has already happened and you're arguing about a finished creature. Here the creature never finished forming, and two centuries later a folklorist and a dictionary are still disagreeing about one letter.