The daughter of a prominent feudal lord in Hoshido, Reina was originally raised to become a lady befitting of her family's social position. This contrasts very starkly with her childhood fascination with the Hoshidan army's training, one that eventually developed into a desire to join the guard. Before departing from her home, Reina's parents gave her an apron in the hopes that it would sway her into consigning to their expectations for her to take up the role of a domestic woman. She elected to go against her parents' wishes, choosing instead to mould herself into a knight. Quickly rising through the military ranks, Reina's efforts were eventually recognized by Mikoto, who promoted her into one of her personal retainers. While she personally saw this as a tremendous honour, Reina's parents thought otherwise and thereafter chose to sever their ties with her. Although hurt by her parents' actions, Reina continued to execute her duties as a knight unfalteringly while retaining the apron given to her as a sign of gratitude to them.