Shinoa Hiragi

She was beat bloody daily by her Elder sister Mahiru and told she was completely useless, this starts when she was four and continued untill Mahiru's death during the events of Catastrophe at sixteen, when Mahiru murders Guren Ichinose's friends when Shinoa was eight. The next she's seen is four years later as a sixteen year old army surveillance officer for the imperial demon army. This is when she meets Yuichiro Hyakuya, a loner who has also suffered from traumatic events.