I started out not caring for Tomori, but this episode made me change my mind. She may seem heartless and cold, but she does care about her friends. Taking leave from school to wait for Yuu to recover while watching (and therefore condoning) all he did was psychotic but really impressive. She understands really well how to lose the one single family member you care about, and even then she knew that Yuu's suffering was more severe because Ayumi is actually dead and it was so sudden.

I've always liked Yuu and Ayumi, so this tragedy really hit me hard. I don't really mind if it's formulaic. That just means it's not new, which is almost everything nowadays. I empathize really well with fictional characters, so Yuu's plight was heartbreaking.