She's a bitch of a sister point blank. My younger sister of several years and I have fought tooth an nail at times to the point of not talking to each other for days. However, we'll always make up and she actually shows that she cares through various ways, i.e hug or whatever...
I've yet to see anything from Kirino that she cares or hell even acknowledges Kyosuke when it's not in her best interest. Maybe I've missed something like an underlining facial expression or whatever. Like the scene where they met each other with him coming out of the bath. I'm not Kakashi and can easily see underneath the underneath...
