At a sushi restaurant in Japan, you may see akami, chutoro, and otoro listed separately even though all three come from tuna. These names are not simply a ranking from low to high quality. They mainly describe which part of the tuna the cut comes from and how much fat it contains.
The boundaries are not completely fixed. There is no single exact line on every tuna where chutoro suddenly becomes otoro. Fat is distributed differently throughout each fish, so the names are used as broad categories based on the character of the cut.
Akami is the leanest of the three and lets you taste the tuna itself more directly. Chutoro has a moderate amount of fat while still retaining some of the more distinct tuna flavor of akami. Otoro is especially fatty, usually coming from the belly area, and tends to be softer, richer, and more intense.
All three can come from the same tuna. There is no separate species called “toro.” As the part of the fish changes, so do the amount of fat, the texture, and the flavor, and the name changes accordingly.
In practice, however, the names can feel a little like a hierarchy because otoro is usually more expensive. Even at a conveyor-belt sushi restaurant, akami may be easy to order without thinking much about the price, while otoro can feel like more of a splurge. So even if people know that akami, chutoro, and otoro are not simply quality grades, otoro can still carry a sense of being something special or luxurious.
That does not mean everyone thinks otoro tastes best. Some people prefer akami because its leaner taste feels more distinctly like tuna, while others prefer the balance of meat and fat in chutoro. Otoro can be delicious for one or two pieces, but several pieces in a row may feel too rich for some people.
The names akami, chutoro, and otoro therefore give diners a quick idea of what to expect before ordering: lean and clean-tasting akami, moderately fatty chutoro, or rich, fatty otoro. At the same time, because the price often rises with the amount of fat, otoro can also feel a little more special even though the names themselves are not a simple ranking of quality.
