...I don't like Yukana...
Emiri Katou would honestly be better the way the character is written... and who the hell said a tsundere had to be unjustified in their behaviour?
A tsundere means you're a bitch to the person you like. Nothing more or less than that.
"Darudere" would be the best term to describe Kyonko, probably. Ever seen Ouran High School Host Club?