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"Itchy Butt Means Good Sardine Catch": Japan's Weirdest Folk Superstitions

Not every piece of folk wisdom has a logical explanation — and honestly, that makes it better.

· 5 min · Togetter

What's going on

Japan has a long tradition of zokushin — folk beliefs and taboos passed down through generations, often tied to specific regions. Some of these, like "don't whistle at night or snakes will come," have plausible-ish explanations (whistling disturbed people's sleep in old houses, snakes are attracted to certain sounds). But a popular idea floating around is that all folk superstitions must have some kind of scientific or practical basis. This thread pushes back on that.

A user posted the original observation that while it's a fun, catchy idea that folk taboos always have logical roots, the reality is that a lot of them are just... completely inexplicable. Their examples: "If your butt itches, you'll get a good sardine catch" (recorded in Iwate, Akita, Ishikawa, and Nagano prefectures) and "Don't lend money to someone with thick leg hair" (Iwate). The thread then became a collective dig through regional oddities — and an attempt to rationalize the ones that might actually make sense.

Comments

The idea that every folk taboo has a scientific explanation is catchy and fun — but that’s just not how it works. So let’s really lean into the weird, inexplicable ones. Like “if your butt itches, you’ll get a good sardine catch” (Iwate, Akita, Ishikawa, Nagano) or “don’t lend money to someone with thick leg hair” (Iwate). More of these, please.
I can’t believe there are actually folk sayings like that where people live…
The ones that clearly never traveled beyond one village are way more interesting than the ones that feel like they’ve absorbed some general wisdom along the way.
Never heard any of these… (Iwate resident)
What is this, I’ve never heard of it… scary… (from Iwate)
What happened in Iwate?
I’m from the Hei region of Iwate where if you said “my butt is itchy~” someone would chime in “big sardine haul!”, but I had no idea about the leg hair thing… wonder where exactly that one’s from. Iwate’s a big place after all.
Nagano catches sardines…?
The fact that it’s said in landlocked Nagano is hilarious.
When you think about it calmly, why is Nagano even in this? Nagano has nothing to do with sardines.
I don’t believe sardines are caught in Shinshu. (“Shinshu” is an old name for Nagano Prefecture, a mountainous inland region.) How on earth did this taboo originate there — the curiosity never ends ^_^
Northern Nagano especially has really strong ties with Niigata and Toyama, so it’s plausible. (Even around Shiojiri in central Nagano they’ve been selling firefly squid for ages, and fishing shops in Matsumoto have surprisingly well-stocked saltwater fishing sections.)
I don’t think Akita actually catches many sardines these days. And with washlets so widespread now, (referring to the Japanese bidet toilet seat, now standard in most homes) there’s probably not as much itching going on either.
The butt-itching one seems like it could be explained as a weather prediction thing — like humidity or something.
It’d be interesting if the conditions under which pinworms aggressively lay eggs happened to overlap with the conditions that draw sardines close to shore.
I always figured thick leg hair = not enough friction to thin it out = someone who doesn’t go outside much = no steady income.
Maybe it’s: thick leg hair → high testosterone → builds muscle easily → if they don’t pay you back, you can’t physically take it from them…? lol
My father used to say “don’t lend money to someone with thick leg hair,” so I asked him why, and he said: people who work hard rub their legs enough to thin out the hair, so thick leg hair means someone who doesn’t work. Made sense and didn’t make sense at the same time. This was in Yamagata.
It’s a bit of a “does and doesn’t make sense” kind of story, but just knowing that a folk belief like that actually exists and that there are people who still say it — I’m genuinely moved. This is one of those moments that makes being online worth it. Thank you so much for sharing this 🙏
My father was born in the early Showa era. (Early Showa refers to the 1920s–30s, a generation that grew up before and during World War II.)
Come to think of it, both my husband and my brother are the reliable type, and both have thin leg hair.
Guess no one’s lending me money then.
“Itchy butt → good sardine catch”: high humidity causes stuffiness → plankton bloom → conditions that bring sardines close to shore → overlaps with fishing season. “Don’t lend to thick leg hair”: thick hair = high testosterone = impulsive = bad at repaying. Also: in old times, people who worked hard wore down their leg hair, so thick hair = lazy.
When there are lots of stink bugs, some say “big snowfall coming” and others say “it’ll be a light snow year” — so “they’re not related” is probably the correct answer.
Around where I live there’s one that says “if your ear itches, money is coming your way.” Is that like… compensation for the discomfort of having an itchy ear?
Well, I think it’s a kind of statistics in a loose sense — like how we lump all kinds of unidentified respiratory illnesses together and call them “colds.” Anyway, it sounds like I won’t be getting any loans in Iwate…
Never mind folk taboos — even in biological evolution, things don’t always have a neat scientific reason behind them.
There’s a real chance that some of these started out as the ancient equivalent of a nonsense internet meme, and somehow ended up being passed down as serious folk wisdom.

My take

The fact that it got passed down at all suggests it must have hit home often enough. Though the hit rate was probably pretty low.

Comments loosely translated for tone.

Source https://togetter.com/li/2702768