HONMAGURO

Bluefin Tuna: The Story Behind Akami, Chutoro and Otoro

Bluefin tuna is one of the most respected ingredients in Japanese sushi. Some pieces can cost more than an entire meal at a good restaurant.

But what makes this fish so valuable? And why can different parts of the same tuna taste completely different?

To understand bluefin tuna, we should start with its history.

The Tuna That Sold for $3.2 Million

In January 2026, a 243 kg bluefin tuna was sold for ¥510.3 million at Tokyo's Toyosu Fish Market. That was approximately US$3.2 million.

The fish came from Ōma in northern Japan. It became the most expensive tuna ever sold at Japan's annual New Year auction.

Of course, this was not a normal market price.

The first tuna auction of the year is a major event in Japan. Buyers compete for the best fish, but winning also brings enormous publicity to their businesses.

The record was partly about tradition and reputation.

Still, it shows how important bluefin tuna has become in Japanese food culture.

What many people do not know is that the most expensive part of tuna today was once considered undesirable.

When Fatty Tuna Was Not Popular

During Japan's Edo period, tuna was already used for sushi. However, people preferred the lean red meat known as Akami.

At that time, refrigeration was limited. Keeping fresh fish in good condition was difficult.

Sushi chefs often prepared Akami using a method called Zuke. The tuna was marinated in soy sauce to help preserve it and develop its flavour.

The fatty belly was harder to handle.

Because of its high fat content, Toro spoiled more easily. It was not valued in the same way it is today.

Things began to change as refrigeration and transportation improved.

Chefs could keep fatty tuna in better condition. People also began to appreciate its softer texture and rich flavour.

Over time, Toro became one of the most desirable ingredients in sushi.

I find this part of tuna's history interesting. The fish itself had not changed. What changed was how people handled it and what they enjoyed eating.

What Makes Bluefin Tuna Special?

There are three main species of bluefin tuna.

Pacific Bluefin Tuna is found in the Pacific Ocean and is particularly important in Japanese sushi.

Atlantic Bluefin Tuna lives in the Atlantic Ocean and Mediterranean Sea. It is the largest bluefin species.

Southern Bluefin Tuna lives mainly in the temperate waters of the Southern Hemisphere.

Bluefin tuna are powerful swimmers. They travel enormous distances and can maintain parts of their bodies at temperatures above the surrounding seawater.

Their diet and feeding conditions influence how much fat they develop.

This is important because not every bluefin tuna has the same meat quality.

Two fish of similar size can have very different fat distributions.

One might have beautiful marbling throughout the belly. Another might be much leaner.

When buying premium tuna, size alone tells us very little about how good the fish will be.

Why Is Bluefin Tuna So Expensive?

The price depends heavily on the quality of the individual fish.

Buyers look closely at the colour of the meat and how the fat is distributed. They also consider the condition of the fish after catching.

Handling is extremely important.

A tuna can have excellent natural quality but lose much of its value through poor handling.

How quickly the fish is chilled and how its temperature is controlled can affect the final result.

Origin also influences the price.

Ōma tuna from northern Japan is particularly famous. The area is known for wild Pacific bluefin caught around the Tsugaru Strait.

During the colder months, tuna feed heavily in these waters. Some develop excellent fat content.

However, coming from Ōma does not automatically make every fish exceptional.

Each tuna still needs to be judged individually.

Another reason for the high price is that the most desirable fatty sections make up only part of the fish.

There is much more lean meat than premium Otoro.

This brings us to the three cuts every sushi chef should understand.

Akami: The Lean Red Meat

Akami (赤身) means red meat.

It is the leanest of the three main cuts and comes mainly from the central muscles and back of the tuna.

Good Akami has a deep red colour with very little visible fat.

The texture is firmer than Toro. Its flavour is clean with a noticeable savoury character.

Because there is less fat, the natural taste of the tuna is easier to recognise.

This is one reason I think Akami deserves more attention.

People often assume the fattiest cut must be the best. But a beautiful piece of Akami can be more enjoyable than average Otoro.

In traditional Edomae sushi, Akami is closely connected to Zuke.

Marinating the meat in soy sauce gives it a deeper flavour. The method also reflects how sushi was prepared before modern refrigeration.

For a sushi chef, learning to recognise good Akami is an important starting point.

You need to understand the flavour of the fish before focusing on its fat.

Chutoro: The Balance of Meat and Fat

Chutoro (中トロ) means medium-fatty tuna.

It comes from areas where the meat contains more fat than Akami but less than Otoro. These sections can be found along the belly and parts of the back.

Chutoro is usually lighter in colour than Akami.

You can often see fine white lines of fat running through the meat.

The texture is softer and the flavour becomes richer.

What makes Chutoro special is the balance.

You still get the natural taste of tuna, but the fat gives it a smoother mouthfeel.

Personally, Chutoro is one of my favourite cuts to work with.

It has enough fat to feel rich without becoming too heavy.

However, not all Chutoro looks the same.

Some pieces are quite lean. Others have enough marbling to look almost like Otoro.

When preparing Chutoro, I pay attention to the fat distribution before deciding how to slice it.

A good cut should allow the guest to enjoy both the meat and its fat.

Otoro: The Richest Part of Tuna

Otoro (大トロ) is the fattiest part of bluefin tuna.

It comes from the belly, with some of the richest sections found closer to the head.

Good Otoro has a pale pink colour with heavy white marbling.

Its texture is very soft.

When eaten at the right temperature, the fat creates the melting sensation that makes Otoro famous.

This is why many people consider it the most luxurious part of tuna.

But Otoro is not always easy to work with.

Some sections contain noticeable connective tissue. If the fish is sliced incorrectly, the texture can become chewy.

The thickness of the slice also matters.

When preparing Otoro for nigiri, I look at the direction of the muscle fibres and how the fat runs through the meat.

I want the guest to experience the soft texture without struggling to bite through the fish.

Otoro is expensive because of its limited availability and high demand.

But remember that expensive ingredients still require good preparation.

Poorly prepared Otoro will never become great nigiri simply because the fish costs more.

Understanding the Three Cuts

Akami, Chutoro and Otoro are not three perfectly separated sections.

The fat content changes gradually throughout the fish.

The belly generally contains more fat than the back. The belly closer to the head is usually richer than the area near the tail.

This means two pieces labelled Chutoro can have noticeably different textures.

Both can still be correctly identified.

When training someone to work with tuna, I think it is important to look at the actual meat rather than relying only on the name of the cut.

Pay attention to the colour. Look at the fat and feel the texture when preparing it.

These details will tell you much more about how the fish should be served.

Good Tuna Does Not Automatically Mean Good Nigiri

Even with excellent tuna, the final result depends on the chef.

The way you slice the fish can change how it feels when eaten.

Temperature matters too.

If fatty tuna is served too cold, its texture can feel firmer and the flavour may be less noticeable.

The sushi rice also needs attention.

A rich piece of Otoro will feel different when paired with Shari than a lean piece of Akami.

The seasoning should support the fish rather than overpower it.

This is something I always keep in mind when making nigiri.

The quality of the ingredient matters, but understanding how to use it matters just as much.

What About Wild and Farmed Bluefin Tuna?

Bluefin tuna can come from different production methods.

Wild tuna are caught directly from the ocean.

Some tuna are captured alive and raised in sea pens before harvesting. This method is known as tuna ranching.

There is also full-cycle farming, where tuna are bred in captivity.

These production methods can influence the fat content and quality of the meat.

Bluefin tuna has also faced serious problems from overfishing.

Pacific bluefin stocks have improved significantly following international conservation efforts. However, responsible fishing and sourcing remain important.

As chefs, we should understand where our ingredients come from.

A high price does not automatically mean a fish was responsibly sourced.

Final Thoughts

Bluefin tuna is an excellent ingredient for learning how much variation can exist within one fish.

Akami gives us the clean flavour of lean tuna. Chutoro offers a balance between meat and fat. Otoro provides the richest texture.

All three can make excellent nigiri when handled properly.

The most expensive cut is not always the best choice.

Sometimes I prefer a well-prepared Akami over a piece of Otoro. It depends on the quality of the fish and the experience I want from that particular nigiri.

The important thing is learning to recognise what makes each cut special.

Take This to Your Next Shift

Next time you work with bluefin tuna, spend a little more time examining the meat before slicing it.

Look at where the fat sits and how the muscle fibres run.

Understanding the fish will help you make better decisions when preparing nigiri.