The Sticky Subject

Japan's most divisive breakfast — the smell, the strings, and why three packs cost less than a coffee

You smell it before you see it. Peel back the thin plastic film on a ¥40 pack of natto and something hits the air - earthy, sharp, faintly ammoniac. Like aged cheese that's been sitting on a warm radiator. The beans are small, dark, slicked with something that catches the light. Stir with your chopsticks and the threads appear: translucent, stretchy, multiplying with every rotation until the whole surface is webbed. This is usually where people outside Japan stop.

I didn't. I live in Tokyo and I eat natto roughly three times a week. But I want to be honest: it took me over a year to get there.

What It Actually Is

Soybeans, fermented with Bacillus subtilis bacteria for about 24 hours at 40 degrees Celsius. The fermentation produces two things that define the experience: polyglutamic acid, which creates the sticky threads (itohiki - "string-pulling"), and a cocktail of pyrazines and ammonia compounds responsible for the smell.^[1] The beans soften but hold their shape. The flavour sits somewhere between soy sauce and strong blue cheese - savoury, slightly bitter, with a deep umami undertow.

You buy it in three-packs at any konbini. Lawson, 7-Eleven, FamilyMart - they all carry it, always near the tofu. ¥100-150 for three 40-50g packs. Inside each pack: the beans, a sachet of soy-based sauce (tare), and a sachet of karashi, the hot yellow mustard. Okame natto, made by Takano Foods, is the brand you'll see everywhere. The cartoon face on the packaging is as recognisable as the Kewpie logo.

How to Eat It

The stirring matters. Traditional wisdom says 30-50 rotations minimum, and the science backs it up: stirring breaks down the glutamic acid chains, making the texture stickier but the flavour milder and slightly sweeter. Go past 100 and the difference plateaus. Some purists insist on 400. I've tested this. At 400, you have very sticky natto and a sore wrist.

After stirring, add the tare and karashi. The order is debated with a seriousness that a ¥120 three-pack doesn't seem to warrant. I add the tare before, the mustard after. Not a hill I'd die on.

Then onto hot rice. Non-negotiable. The heat softens the beans further and tames the smell. Sliced spring onion on top is standard. A raw egg yolk is optional but good. The whole thing - sticky, savoury, sharp from the mustard, grounded by plain rice - is satisfying once you're past the barrier.

The Regional Divide

Japan isn't unanimous about natto. The country splits roughly east-west. Kanto - Tokyo, Saitama, Ibaraki, Tochigi - eats it regularly. Kansai - Osaka, Kyoto, Kobe - largely doesn't.^[2] Per-capita consumption in the east runs roughly twice the rate of the west.

Ibaraki Prefecture claims to be natto's birthplace. Mito natto is a regional identity marker the way Kobe beef is in Hyogo. Ask someone from Osaka about natto and you'll get a look of polite disinterest. Ask someone from Mito and you'll get a lecture.

Why the split? Partly climate, partly historical soybean cultivation, partly Kansai's preference for subtler, dashi-forward flavours. Natto's assertiveness doesn't sit well next to that. But the divide has narrowed over the decades. It's a gradient now, not a wall.

Why I Eat It

I'm going to skip the nutritional pitch, mostly. Per 50g serving: about 100 calories, 8g of protein, significant vitamin K2, iron, fibre. The fermentation makes the soy protein more digestible than in straight soybeans.^[3] There's an enzyme called nattokinase that Western supplement companies have latched onto for cardiovascular claims. The research is ongoing. I don't eat natto because of nattokinase. I eat it because it's breakfast.

A bowl of rice, miso soup, a pack of natto with spring onion. Three minutes to prepare. Keeps me full until lunch. ¥100 for the natto, maybe ¥30 for the rice. Can you find a cheaper, more nutritious breakfast in Tokyo? I can't.

The texture is the real barrier, not the smell. The smell fades the moment the natto touches hot rice. But the threads - stretching from your chopsticks to the bowl to your chin if you're not careful - that takes some getting used to. Food in the West is expected to behave. Natto doesn't cooperate.

The Verdict

I like natto. I didn't always. The gap between those two states was filled with a lot of rice, a lot of mustard, and the kind of stubbornness that probably says more about me than the food.

What converted me was the routine. Not the flavour, not the health claims - just the ritual of it, same bowl every morning, unremarkable and sustaining. The people who dismiss natto after one attempt are missing the point. So are the people who perform enthusiasm for it on social media. Natto doesn't reward first impressions. It rewards repetition.

Should you try it? Probably. Will you like it? Honestly, maybe not. But it costs less than a vending machine coffee and it'll tell you something about your own willingness to be uncomfortable for three minutes. That's a fair deal.