is the term applied to the
doitsu version of
The term 'shusui' translates to 'autumn water.'
Just like an asagi, the top half of the body of a shusui is
also light bluish in color, while its undersides exhibit red or
orange markings. Being a doitsu though, the shusui can
not exhibit a netting effect like an asagi, since it has no
scales to show reticulation. Instead, an important
feature of a shusui is its line of mirror scales running along
its spine from the back of the head to its tail.
refers to a shusui koi whose blue body is almost completely
covered with red coloration. A hi shusui that exhibits
blue mirror scales on both lateral lines is known as
The Shusui's body must be blue in color above the lateral
line. The blue color must be of even shade and hue
within a single koi, although it may vary from one koi to
Aside from the blue color of the shusui above its lateral line,
it must have red coloration on the underside of the its body,
just below the lateral line. This red color may also
appear on all fins, the gill covers, and mouth.
The mirror scales of a shusui along its back must be in a straight row with
no gaps in between from the back of the head to its tail. The head of a shusui must be clean,
i.e., it must not exhibit any imperfections or small black
Please see separate article on
The Ideal Koi Body.