Aya Ruobing, who was trained at an international spy killer school from the age of 3, graduated as a professional killer elite at the age of 16, worked for the organization "Sanye Club", and enrolled in Class A of the Royal Noble School in order to complete a mission. Just to kill a 16-year-old boy - Shun Sato, and later found out that she was actually the daughter of the leader of Sanya Club...