as much as i like this manga, i dont understand why yamada and kase dont trust each other. relationships are built on trust and they both showed scenarios where they show a good amount of trust where they should know that the other won't cheat or something then it gets thrown out the window with...
it seems like touko's approach is to make sure that the main girl belongs only to her. my guess next chapter is going to be her trying to get her mad at rin or kiss rin in front of her