A girl named Katie Azuma the second daughter of the Azuma family has been sexually harassed and abused by her own parents for the past 17 years. But, ever since she has moved to her grandmothers house, her grandmother had signed her up to an assassination class to train and to be able to kill a man or woman as their target. But instead of killing, she protects the target she's supposed to kill by fighting back to all 11 people that are planning on killing their target.