Okay so Shiori IS a tsundere and was pretending. And she is like Miko, but was probably not approving of Miko's methods, instead using mindgames and force to make Hinako be happier. I suppose she could have been lurking in the background before, watching over Hinako and Miko, but I'm not sure. Satisfactory. And yeah next conflict is probably something similar to what the commenter above me said.