Rakudai Seijo na no ni Seijo ga Kirai na Henkyou Haku ni Dekiai Saretemasu

Liliana, the daughter of an earl, is known as a "useless, failed saint"—a hopeless dropout in everyone's eyes. But in truth, her magical power had been constantly stolen by her half-sister, which is why she was never able to show her true abilities. One day, a marriage proposal arrives from the marquess of a neighbouring country. The current head of the family, Sirius Lundvall, clearly states "I hate saints." Although Liliana isn't enthusiastic about the proposal, she can't turn it down and ends up marrying him. As expected, Sirius is cold and distant toward her at first. However, as he begins to see Liliana's honest and sincere nature, he slowly starts to open his heart to her, and the two gradually grow closer… Original Webtoon: CMOA, eBook Japan, LINE Webtoon