Shusui have been crossbred between Doitsu Koi and Asagi, and their points for appreciation, therefore, are basically the same as those for Asagi.
Shusui also have the tendency to show black spots in the head region as they grow big. Koi with spotless head region are valued highly, of course.
The arrangement of scales is also important. It is desirable that scales are visible only the back and the regions of lateral lines -- no undesirable scales in any other place. Hi on the belly covering over the lateral lines are showy.
After the water temperature in your pond drops to 60 degrees or below, you should decrease the amount of food given to your fish and feed them no more than once a day. Ask your dealer about a food designed for cool weather feeding.