Aquarium Koi Judging Terms Glossary Guide: Sashi Kiwa Hi Sumi

Walk into any koi show in Japan or Singapore and listen to the judges and you will hear a vocabulary almost entirely drawn from Japanese aesthetics — sashi, kiwa, hi, sumi, shiroji. The aquarium koi judging glossary below decodes the terms a Zen Nippon Airinkai (ZNA) judge uses to evaluate body, skin, pattern and deportment. Whether buying a Kohaku at Aquarama or selecting from a local breeder, this aquarium koi judging glossary from Gensou Aquascaping at 5 Everton Park gives you the framework to assess quality on the same basis judges use.

Definition in 50 Words

Koi judging assesses ornamental Nishikigoi (Cyprinus rubrofuscus domesticated variants) on body conformation, skin quality, pattern, colour and deportment. Standard ZNA scoring weights body 25 per cent, skin 25 per cent, pattern 25 per cent and deportment 25 per cent. A vocabulary of Japanese terms describes the specific qualities judges look for at every level.

Hi: The Red

Hi (pronounced “hee”) refers to red pigmentation. Quality hi shows deep, even saturation across the entire patch — uniform colour with no fading toward edges. Orange-leaning hi is less prized than crimson. Surface hi sits visibly on top; deep hi penetrates the skin and resists fading with age. Kohaku and Sanke fish are evaluated heavily on hi quality and distribution.

Sumi: The Black

Sumi is black pigmentation, present in Sanke, Showa, Bekko, Utsuri and many other varieties. Quality sumi shows lacquer-deep blackness rising from the skin like ink. Sumi often emerges and shifts as koi mature — young Showa may show grey sumi that deepens over 3-5 years. Stable, well-shaped sumi patches with crisp edges score highest.

Shiroji: The White

Shiroji is the white skin background. In Kohaku and Sanke, shiroji must be snow-white — not cream, yellow, or grey-tinted. Pure shiroji free of grey patches or blemishes is exceedingly rare and commands premium prices. Stress and water quality issues dull shiroji within weeks; high-end koi from the koi range need pristine water to maintain show-grade white.

Sashi: The Forward Edge

Sashi describes the leading edge of a hi or sumi pattern as it transitions into shiroji. A clean, sharp sashi edge — looking like cut paper — is a hallmark of quality. Soft, blurred, fading sashi reads as poor pattern resolution. Judges examine sashi sharpness with raking light to detect any blur or pixelation.

Kiwa: The Trailing Edge

Kiwa describes the rear (trailing) edge of a pattern, where the colour ends. Kiwa quality matters as much as sashi — a fish with sharp sashi but blurred kiwa reads as unbalanced. The crispest kiwa appears at scale boundaries, where the edge follows scale lines rather than cutting across them mid-scale. Top fish show kiwa precision on every edge of every patch.

Body Conformation (Sugata)

Sugata is the body shape and proportion. Judges look for symmetric body lines from above — left and right halves should mirror each other. The body should be pleasingly rounded with strong shoulders, smooth dorsal line, and proportionate fins. Curvature, asymmetry, deformed jaws or twisted spines lose points. Body weighs 25 per cent of the total ZNA score.

Skin Quality (Hada)

Hada refers to overall skin condition — the quality of the substrate on which patterns sit. Healthy hada shows lustre, depth and a subtle metallic sheen under good lighting. Pinkish nuance in shiroji can signal good skin tension; grey hada signals stress. Skin quality also weighs 25 per cent and depends heavily on water quality maintained with the water care range.

Pattern Distribution

Pattern weighs another 25 per cent. Kohaku patterns prefer balanced hi distribution along the body — not too head-heavy, not tail-heavy, with a clean break before the tail (ozutsu). Sanke adds sumi accents that should be balanced along both flanks without dominating. Showa carries heavier sumi that wraps the body, with hi and shiroji appearing through it. The aesthetic ideal is asymmetric balance — never perfectly mirrored, never random.

Deportment (Hinkaku)

Hinkaku is the koi’s bearing, presence and charisma — the hardest quality to teach. A high-deportment koi swims with quiet authority, holds itself at the water surface during inspection without panic, and projects calm confidence. This 25 per cent of the score is partly genetics, partly conditioning. Champion koi from established Japanese bloodlines (Sakai, Dainichi, Marudo) show hinkaku from juvenile age.

Singapore Show Notes

Local koi shows at Aquarama and the Singapore Koi Club follow ZNA-aligned criteria. Show pond water is held at 20-22°C with crystal clarity to bring out skin lustre — well below tropical ambient. A chiller from the chiller range is essential for show-grade conditioning. Quality koi food rotation from the koi food range directly affects hi colour and shiroji clarity over the months leading up to a show.

Related Reading

• Koi Fish Care Guide Singapore
• Kohaku Koi Variety Guide
• Sanke Koi Variety Guide
• Showa Koi Variety Guide
• Aquarium Fish Scale Types Glossary Guide