The Showa is one of the big three of the Go Sanke Koi varietals (Kohaku and Sanke being the other two). It is most often confused with a Sanke, as the Showa is traditionally assumed to be a black Koi, white (shiroji) and red (hi) markings, whereas a Sanke is a white Koi with black (sumi) and red (hi) markings.
One of the tricks in telling these two apart is that a Showa has black (sumi) on it’s head, whereas a Sanke (ideally) does not.
Also, if you note the pectoral fins you will see that a Showa often has a good dollop of black (sumi) in it’s pectoral fins. Often this black (sumi) is streaked and this is a much desired attribute.
Showa are also much treasured Koi and are one of the older varieties. As with matters Go Sanke, clean crisp lines of colour markings are favoured with purity of colour more important that the actual hue. In other words, variation within the colour is less desirable than the colour itself. This is normally most applicable to the red (hi) which can vary substantially from a deep red (better) to orange, or anywhere in between.
Consistency however is of far more value than the actual shade of red (hi).
Showa Koi are stunning fish. A good Showa is difficult to beat and every Koi pond needs a stunner. A more classic Koi would be hard to find, save perhaps a Kohaku or Sanke.
In the meantime, below is a picture of yet another stunner. Once more you can see the desirable crisp lines of how the red (hi), black (sumi) and shiroji (white) are clearly defined. This Showa’s pectoral fins do not have as much black (sumi) streaking as might be seen on some other Showa, but nonetheless this is a classic example of the very best of the variety.
More about the Showa Koi here