In the world where power combat determines a person's role in the society, a young and talentless girl, Chitose Asahina has been abandoned by her own family since she was young. After the events, a middle-aged woman meets the abandoned girl. She takes her in and treats her like her own daughter. Now that she is 18, she is determined to prove to her family that she can be useful, and tries out her luck by training hard and studying well in the nearest High School, in order to fulfill her dream of joining the most powerful and prestigious guild in the region. One day, she meets a mysterious assassin, who was ordered to kill her, but before that happens, he gives her an offer that could change her life upside down.