Cuts

Japanese Fish & Sashimi Cuts

Kakushi-bocho (Hidden Score Cuts)

Also: kakushi bōchō, hidden knife, invisible scores, ura-kiri

Shallow incisions made on the unseen side of fish or vegetables so heat penetrates evenly and the food folds or curls without cracking the skin.

Kakushi-bōchō (隠し包丁, 'hidden knife') is the practice of making shallow cuts on the underside — or interior face — of fish, fillets, or dense vegetables before cooking. The cuts are positioned so they are invisible once the food is plated presentation-side up. Their purpose is functional: they break through connective tissue and muscle walls that would otherwise resist heat, allowing steam and radiant heat to reach the centre without overcooking the surface.

In photos

Kakushi-bocho (Hidden Score Cuts) in its raw whole-cut form on a butcher's board — Kakushi-bōchō (隠し包丁, 'hidden knife') is the practice of making shallow cuts on the underside — or interior face — of fish, fillets, or dense vegetables before cooking. Identifying traits: Invisible from the presentation side — cuts face down or inward, Shallow depth: typically one-third to half the thickness of the flesh, Parallel or cross-hatch pattern depending on anatomy and intended movement.
Kakushi-bocho (Hidden Score Cuts) in its raw whole-cut form on a butcher's board — Kakushi-bōchō (隠し包丁, 'hidden knife') is the practice of making shallow cuts on the underside — or interior face — of fish, fillets, or dense vegetables before cooking. Identifying traits: Invisible from the presentation side — cuts face down or inward, Shallow depth: typically one-third to half the thickness of the flesh, Parallel or cross-hatch pattern depending on anatomy and intended movement.
Where the kakushi-bocho (hidden score cuts) lives on the source. Applied to the flesh side of whole fish or fillets (usually the belly or dorsal underside), to the interior of folded vegetables like cucumber or eggplant, or to the concave face of shrimp to prevent….
Where the kakushi-bocho (hidden score cuts) lives on the source. Applied to the flesh side of whole fish or fillets (usually the belly or dorsal underside), to the interior of folded vegetables like cucumber or eggplant, or to the concave face of shrimp to prevent….
Kakushi-bocho (Hidden Score Cuts) prepared the canonical way — Tai no shioyaki (salt-grilled sea bream). Pat the fish or vegetable completely dry so the knife doesn't slip on moisture.
Kakushi-bocho (Hidden Score Cuts) prepared the canonical way — Tai no shioyaki (salt-grilled sea bream). Pat the fish or vegetable completely dry so the knife doesn't slip on moisture.

Where it comes from

Applied to the flesh side of whole fish or fillets (usually the belly or dorsal underside), to the interior of folded vegetables like cucumber or eggplant, or to the concave face of shrimp to prevent curling. The cut never penetrates the skin or outer surface that will face the diner.

Invisible from the presentation side — cuts face down or inwardShallow depth: typically one-third to half the thickness of the fleshParallel or cross-hatch pattern depending on anatomy and intended movementEnables controlled curling or cupping without skin tearingReduces internal cooking time without altering surface appearanceUsed on both protein and vegetable subjects

Best for

Yakimono (grilled fish on binchotan or gas grill)Mushimono (steamed whole fish)Nimono (simmered fish and root vegetables)Deep-frying whole fish or scored eggplantKaiseki garnish vegetables requiring precise fold or curl

How to cook it

  1. 1Pat the fish or vegetable completely dry so the knife doesn't slip on moisture.
  2. 2Hold the subject presentation-side down; identify the underside or interior face where the cuts will be hidden.
  3. 3Draw the yanagiba or deba in clean, confident strokes at roughly a 30-degree angle to the flesh, spacing cuts 8–12 mm apart. Depth should reach halfway but not puncture the skin.
  4. 4For fish with a thick spine line, make cuts on both sides of the backbone channel to ensure even heat penetration near the bone.
  5. 5On round vegetables like eggplant or cucumber intended to spiral or fold, space cuts closer together (5–6 mm) and slightly deeper.
  6. 6Proceed with the cooking method immediately; scored surfaces dry out quickly and may split if left uncovered for more than a few minutes.
  7. 7When plating, place scored side down or inward — the presentation surface should show no knife work.

Prep & butchery

  • Use a freshly sharpened yanagiba or thin deba — a dull blade drags and tears rather than slicing cleanly, destroying the 'invisible' quality.
  • Score at a shallow angle (30°) rather than perpendicular so cuts fan open gently during cooking rather than gaping.
  • On whole fish, remove scales before scoring; scales cause the blade to skip.
  • For vegetables, peel or retain skin as required by the recipe — scoring through unpeeled aubergine skin is intentional when a purple stripe is desired.

Substitutes

  • kazari-giri visible scoring

    For decorative rather than functional purposes, scores are placed on the visible face; flavour penetration is similar but presentation intent differs.

  • Prick with skewer

    A coarser alternative for thick fillets; lacks the controlled-fold precision of hidden scoring.

Related cuts

  • Kazari-giri

    The visible counterpart: decorative surface scoring placed on the presentation face.

  • Sogigiri

    Diagonal slicing of fish flesh; often performed before or after kakushi-bōchō on the same fillet.

  • Keirimen

    Cross-hatch scoring on fish skin to prevent curling during dry-heat cooking — related functional category.

Appears in

Tai no shioyaki (salt-grilled sea bream)Saba no miso-ni (mackerel simmered in miso)Nasu dengaku (miso-glazed eggplant)Karei no karaage (deep-fried flounder)

References

  1. 1.Japanese Cooking: A Simple Art — Shizuo Tsuji
  2. 2.The Japanese Kitchen — Hiroko Shimbo
  3. 3.Washoku: Recipes from the Japanese Home Kitchen — Elizabeth Andoh

Confidence: high

Notes

Why 'hidden'?

Japanese culinary aesthetics prize surfaces that appear unmanipulated. The kakushi-bōchō philosophy reflects the broader washoku ideal that craft should be felt in the eating — even heat, yielding texture — but never announced visually. A diner consuming a perfectly grilled tai fillet has no idea the back of the fish carries a map of parallel incisions.

Vegetable applications

Hidden scoring is especially important in nimono. Dense root vegetables like daikon or gobo resist heat at their core; scoring the interior face (cut into quarters, then scored before reassembling) allows dashi to permeate deeply during simmering. The vegetable maintains its round shape while cooking through completely.