Dusk Maiden of Amnesia/Nightmare Fuel


 * The manga opens with the shadowy image of a crying girl and a tale of a girl being sacrificed to protect the school. Now consider that we learn Yuuko was not only sealed in that underground space, but that she also had a broken leg. She died, scared, alone, pleading for help, and in pain.
 * Episode 4 of the anime gives us our first proper look at Shadow Yuuko as she stands over a sleeping Kirie, displaying a full on Slasher Smile full of dagger-like teeth.
 * Episode 6: Kirishima Yuuko being offered up as a sacrifice for the fictitious monster that she created as part of a Batman Gambit that had Gone Horribly Right. People she thought of as friends were willing to kill her to save their own skin, and the worst part is, there wasn't even any malice towards her when they were going to do it.