Japan (Tokyo Bay historically; Tsugaru Strait and Atlantic/Pacific deep waters; Toyosu market as the pricing and quality benchmark)
Honmaguro (本鮪, Pacific bluefin tuna — Thunnus orientalis) is Japan's most prestigious fish and the subject of elaborate anatomical understanding that goes far beyond any other species in Japanese cuisine. The full value hierarchy of tuna cuts in Japanese cuisine runs from the most expensive (otoro, the extreme fatty belly near the head) through chutoro (medium fatty), akami (lean red flesh — the flank and back), and multiple specialty cuts: kama-toro (collar fat), the highly prized hoho-niku (cheek meat), and the collar cut. Otoro itself has sub-varieties: the most fatty part near the belly-head junction, and the triangular 'sanku' cut prized at premium sushi. Chutoro sits along the middle-belly and the upper back areas where medium fat infiltration produces a balance of fat and lean that many connoisseurs prefer over pure otoro's heaviness. Akami has experienced remarkable culinary renaissance — the finest maguro zuke (akami marinated in soy) at Edomae sushi represents the depth that lean can achieve. The jaw and cheek area produce small amounts of extraordinary hoho-niku, with gelatinous, fat-marbled flesh unlike any other part. Kama (collar, including the pectoral fin area) is one of Japan's great grilled preparations — eaten at large, the collar reveals a range of textures from crisp-grilled skin through fatty tuna adjacent to the collar bone.
Otoro: melt-on-tongue fat richness; chutoro: balanced umami-fat harmony; akami: clean iron-mineral lean depth; cheek: gelatinous richness; collar: roasted fat and caramelised skin
{"Otoro: extreme belly fat from head area — highest price, maximum fat, near-melting texture","Chutoro: medium fat, flank and upper back — balance of fat and lean preferred by many connoisseurs","Akami: lean red flesh — properly marinated (zuke) shows remarkable depth","Hoho-niku (cheek): tiny quantity per fish, gelatinous fat texture, extraordinary flavour","Kama (collar): grilled whole — range of textures from crisp skin to fatty meat adjacent to bone"}
{"At Toyosu market tuna auction: the year's most expensive honmaguro (New Year's first auction) can reach hundreds of millions of yen","Akami zuke: marinate in equal parts soy and sake for 20–40 minutes; wipe and slice for nigiri — transforms lean tuna","Hoho-niku: ask specifically at high-end counter — the chef controls allocation; a rare privilege when offered","Negitoro (minced toro with scallion): a traditional use of collar and trim fatty tuna mixed with scallion for gunkan rolls"}
{"Assuming otoro is always superior — chutoro's balance often provides more complex eating experience","Serving akami without considering zuke preparation — lean tuna benefits enormously from brief soy marination","Ordering kama expecting large quantities of meat — collar meat is extractive, requiring work at the bone","Assuming all honmaguro is equal — farm-raised Pacific bluefin vs wild Atlantic bluefin are categorically different"}
The Sushi Economy — Sasha Issenberg; Japanese Cooking: A Simple Art — Shizuo Tsuji