Dog & Scissors: Madoka Harumi

 Madoka is the athletic and popular little sister of Kazuhito.  After her brothers deaths she seemed to realized that he was now in the body of Kirihimes dog.  She was correct; however, it turns out she did not actually know that and it was just grief that made her think that.  Madoka carries a 'knife' that can turn into a variety of weapons such as a chainsaw.