Kirika fucked up when spreading luring powder during a dungeon training run, tons of people die, Amelia kills the monsters and resurrects everyone, father wipes everyone's memory of the event and subsequently of Kirika in order to protect her from being crushed by the guilt, Kirika develops an inferiority complex towards Amelia(because their father thought she was too young to learn the truth and never told her, kept putting it off because she seemed so composed(TOTALLY MAKES SENSE RIGHT?)) and plots to usurp everything she has, Kirika proceeds to use her charm on literally everyone, including the King(who never realized it somehow) and Amelia(which is why she is so self-depreciative now), leads to Amelia getting labeled a criminal and exiled, no one is punished and Kirika and the King just say oops our bad once the charm is dropped and he reveals the truth of what Kirika did. Oh and the King didn't wipe Amelia's memory either which just compounds how monumentally stupid all the shit that happened thereafter is.