You may think konatsu is selfish but I don't see it as that, at least not completely.
Koyuki was the one who needed the most help, konatsu did everything she could to help her while she too has difficulties with loneliness. She even turned a blind eye to konatsu's opening with other students, but koyuki also met kaede behind her back...
Anyway at one point konatsu couldn't take it all anymore, especially when she understands that koyuki didn't notice her own suffering.
Now I think we're going to enter the bow with koyuki's point of view and it's up to her now to do something for konatsu and not stay as passive as a robot. It's time for koyuki to take the next step and help and understand the person most dear to her at school. Because doing nothing and hiding important things is also a form of egoism.