Hello Koi Friends, enthusiasts, and budding hobbyist. One of the more fun things about koi keeping is learning the terminology of koi. There are so many fun new words and descriptions to learn in this hobby.

Summarized below is a collection of Japanese Koi terminology used by koi breeders, koi dealers and enthusiasts alike to describe the most desirable features and uniqueness of koi. You'll notice that many of these Japanese terms are taken from nature. The Japanese celebrate beauty in nature, as also demonstrated by bonsai gardens and ikebana flower arranging. 

I will continue to add to this list as I learn. Feel free to make suggestions as well as you learn of terms that should be added here


Koi Body Terms:

  • Hana: nose (shape is important)
  • Hachi: head or forehead, in front of dorsal fins
  • Kata: shoulder area, in front of dorsal fin. At first look, your eyes go immediately to the kata, so shape is important and a hump is impressive. The goal is to get them big and large like football players. This is where they store fat to help them over the winter
  • Hire: fin (hire nga: long fin)
  • Ozutsu: area of dorsal fin to tail section. Uniform shape is very important
  • Odome: space between the last step of color and the tail. It is important that white separates color and tail, especially on Kohaku

Koi Pattern Terms (Toyo):

  • Sashi: front edges of a pattern
  • Kiwa: back edges of a pattern
  • Nidan: 2 step pattern
  • Sandan: 3 step pattern
  • Muji: solid color (literally 'solid ground"). Example: aka muji: red koi
  • Tancho: Kohaku with red only on its head
  • Maruten: a patterned koi which includes a red spot on the head

Koi Color Terms

  • Hi: red markings (literally "flame"), usually describes the red on a Showa or Utsuri. It used to be more persimmon or orange in color, but newer breeders are now going for a cherry red
  • Beni: red, typically used to describe the red on a Kohaku or Sanke (now cherry red too)
  • Aka: red that is a crimson or brownish-red found on a Matsuba or Aka Bekko
  • Sumi: black markings on any koi. The name is taken from sumi ink, which is made from charcoal and is a deep black.
  • Shiro: white base or literally "white ground".

Koi Pattern Terms (Sumi):

  • Tejima: black stripes on pectoral fin, appears on Sanke, not Showa.
  • Kasane sumi: black on top of red (old school).
  • Tsubo sumi: black that sits outside of red or next to red. This clean look is currently popular.
  • Kata sumi: black on shoulder, very important for Sanke to have this as the first step.
  • Kagi sumi: "shadow,” an ethereal gray-black look that applies to mostly Showa and Utsuri.
  • Moto guro: black on base of pectoral fin, only seen on Showa and Utsuri.

Koi Age Terms:

  • Kego: fry stage.
  • Tosai: during first year of life, usually when koi are put into the mud pond.
  • Ake Nisai: early in second year of life, usually when koi are brought back into the greenhouse.
  • Nisai: 2nd year of life
  • Ake Sansai: Early in the 3rd year of life
  • Sansai: Third year of life
  • Yonsai: forth year of life


I will continue to add to this list as I learn additional terms. Feel free to make suggestions in the comments below.  

Koi terminology

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