Yor Briar grew up in a with no parents just a brother, deeply impacted by her brother and her own desire to protect them. She embraced her quiet nature while making friends who often labeled her naive. Initially, she took the job at city hall to provide stability and contribute to society positively. However, unbeknownst to her colleagues, Yor entered the ordell of being the Thorn Princess - a proficient assassin who had no ties to her job. This dual life began after she stumbled upon a dark secret of a criminal organization while trying to protect her brother, who was in danger. She saw the necessity of becoming an assassin to defend those she loves, resulting in an unpredictable balance between her gentle persona and lethal alter-ego.