Major groups to learn next
| Group | Identification cue | Quality cue |
|---|---|---|
| Shusui | Doitsu Asagi relative with mirror scales along the back. | Neat dorsal scale line, clean head, controlled red on sides. |
| Goromo / Koromo | Kohaku-like red pattern with blue/dark edging over the red. | Clean white ground and reticulation that enhances rather than dirties the beni. |
| Goshiki | Five-color impression, often red pattern over darker reticulated ground. | Clear red pattern, balanced dark ground, no muddy confusion. |
| Kujaku | Metallic koi with reticulation and orange/red pattern. | Strong metallic sheen plus orderly reticulation. |
| Chagoi / Soragoi / Ochiba | Single-color or autumn-leaf pond favorites. | Body, scale neatness, calm behavior, and even color. |
| Gin Rin / Doitsu | Cross-cutting scale traits, not always standalone varieties. | Even sparkle for Gin Rin; neat scale rows for Doitsu. |
- Shusui
- The Doitsu relative of Asagi, known for mirror scales along the back and red side accents.
- Goromo / Koromo
- Kohaku-like pattern with blue or dark edging over the red markings, including Ai Goromo and Budo Goromo.
- Goshiki
- A five-color impression that can combine Kohaku-like red with darker reticulated ground.
- Kujaku
- A metallic koi with reticulation and orange or red pattern, often grouped under Hikari-moyo.
- Kawarimono
- A broad non-metallic category for varieties that do not fit other major classes, including Chagoi, Soragoi, and Ochiba Shigure.
- Gin Rin
- A sparkling scale effect that can appear across many varieties.
- Doitsu
- A scale type with few or no regular scales, often showing larger mirror scales along the dorsal line.
- Butterfly Koi / Longfin
- A long-fin form popular in aquarium viewing. See the dedicated tank-care guide for water volume, filtration, and fin protection.
This page is now a map into the expanded non-Gosanke library. Each linked page includes a whole-fish image, a study diagram, and practical identification notes.