The Showa , developed in the 1930's, features white and red markings against a jet black base. The sumi (black) is the basis for appreciation of this variety, forming a strong background against which the white and red markings interweave in interesting patterns. Showa that have comparatively more white than black are called Kindai (modern) Showa.

A showa should also have black on the face (preferably the nose), and in an ideal world, all three colors should be present in this area. In a really, really, really ideal world, the arrangement of the three colors on the face is mirrored in reverse at the other end of the koi. Ergo, if the tip of the face is white, followed by red and then black, then the rear portion of the fish's body should be black, followed by red and finally white.

Breeders of showa try very hard to create koi that have a sumi mark on the head that resembles a diagonal band of lightning. This trait is referred to as hachiware or menware, and this characteristic helps give a showa its imposing appearance. Another trait that adds to this image of power is motoguro, the presence of black at the base of each pectoral fin. It is preferable that these black markings not go as far as the edge of the fins and that they be surrounded by white on all three sides. It can take many years for complete development of the sumi to take place.