Ruka is hellbent on knowing the full story behind Kazuya and Chizuru's relationship, and once she does she decides to take action.
How do you know them, Ruka-san?
كيف تعرّفتِ عليهما يا روكا-سان؟
Woher kennt ihr euch, Ruka-san?
Au fait,
comment les as-tu connus, Ruka ?
Come avete conosciuto Ruka?
Ruka-san, como você os conheceu?
А как ты с ними познакомилась, Рука?