After her family was murdered, Lucina was left to outrun whatever was coming after her before being rescued by the Black Aconite, a crime organization. They raised and taught her weaponry skills, Lucina became proficient with sniping, but despite learning to fight and shoot, she lacked the conviction to kill. Kuroh was assigned as her partner, a mysterious ruthless individual. Both have a goal that conflicts with one another that would lead one being unable to achieve if the other attain theirs.