Watashi no Konyakusha wa, Nekura de Inki dato Iwareru Yami Majutsushi desu. Suki.

Overview

Countess Lydia is on the verge of her family's downfall when her father is falsely accused of assaulting the princess. One day, however, she is suddenly informed that her father's innocence has been proven. A dark magician named Reges has demanded that the family's reputation be cleared as a reward for his achievements. Why has he saved the count's family, even though they have no connection to him?! A love comedy between a simple and powerful dark magician and a beautiful countess! (Source: Kadokawa, translated)

Source: AniList