Natto: Japan's most polarising food

Natto (納豆) is soybeans fermented with a bacteria called Bacillus subtilis natto. It has a strong smell, a sticky texture, and a flavour that divides people — including within Japan itself. It’s also one of the most widely consumed foods in the country, especially at breakfast, and a point of regional pride for Ibaraki Prefecture, where the historically best natto is produced.

What it’s like

When you open a pack of natto you find soybeans coated in a web of white, viscous threads. When you stir them with chopsticks, those threads stretch into strings that can extend several centimetres. The smell is intense — comparable to a strong blue cheese, with ammonia notes — and for someone opening it for the first time, it can be quite alarming.

The flavour is deep umami, slightly bitter, with a persistent aftertaste. Inside the pack there are usually two small sachets: Japanese mustard (karashi) and soy sauce. Both go in before mixing.

How to eat it

The standard way is over a bowl of hot white rice. Mix it well before eating — the more you stir, the more threads form, and Japanese people consider this the right way to do it. Some add chopped spring onion, a raw egg, or an extra splash of soy sauce.

A tip for first-timers: hikiwari natto (挽き割り納豆), which uses ground soybeans instead of whole ones, has a less intimidating texture and a slightly milder flavour. It’s the recommended variety if it’s your first time.

When and where

Natto is primarily breakfast food, though it also appears at dinner. You can buy it at any convenience store — 7-Eleven, Lawson, FamilyMart — in packs of three for around ¥100. Supermarkets have a wider selection with more brands and varieties.

Some teishoku chains like Nakau or Yoshinoya include it as part of their breakfast sets alongside rice, miso soup, and an egg.

The Kanto–Kansai divide

Natto is far more popular in Kanto (Tokyo and surroundings) than in Kansai (Osaka, Kyoto). This cultural divide is real and well-documented: consumption surveys consistently show that Osaka residents eat significantly less of it, and in some traditional Kansai circles it carries a reputation as “Tokyoite food”. Nobody is entirely sure why this geographical boundary formed, but it has been entrenched for decades.

Why people eat it

Beyond the flavour, natto has a well-founded reputation as a healthy food. It’s high in plant-based protein, vitamin K2 (important for bone and cardiovascular health), and contains an enzyme called nattokinase, which is believed to have anticoagulant effects. It’s inexpensive, keeps well in the fridge, and takes about thirty seconds to prepare. In the context of a Japanese breakfast, it fits perfectly.

How to try it without drama

If you decide to give it a go, some practical advice:

Buy it at a convenience store before breakfast. Don’t smell it before mixing — that’s the moment when the odour is most intense. Mix it well into the rice before the first bite, so the flavour isn’t isolated. And give it a second chance: natto is one of those foods that people almost always like considerably more on the second try than the first.

If natto sounds manageable, there’s a whole category of Japanese foods that surprise Western visitors that go quite a bit further.

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