An Indomitable Prodigy (E03)

Annerose, Reinhard's older sister, lives in the palace as the kaiser's favorite mistress. As Reinhard and Kircheis make their way to her residence for a visit, they both recall memories of their childhood together. Then Annerose, after greeting them with a smile that hasn't changed since they were young, asks Kircheis to continue looking our for her brother and guide him back toward the right path if he ever goes astray. (Crunchyroll)