Ruka Shinoda/Plot

Background
Five years before the start of the Manga, Ruka's home country, Aristera, was destroyed. Ruka and her brother are former members of the Aristeran royal family. During the chaos of the war, Border helped them escape their home with Aristera's Mother Trigger. Currently, Border shelters both Ruka and Yōtarō. Ruka uses Masafumi Shinoda's last name as a cover while Yōtarō uses Takumi Rindō's. Ruka acts as the operator for Border's (formerly Aristera's) Mother Trigger.

Away Mission Test Arc
Ruka comes to the Tamakoma Branch base to visit Yōtarō.