Konse wa, hitori de ikiyou to omoimasu. Sono hazu ga...

Synopsis:

"This time, I'll take my life into my own hands." Maricia, the daughter of a marquis, is shunned by her family because she can't use magic. Her fiance, Heinrich, was her sole source of support, but she discovers he's having an affair with her stepsister, Cannolina! The shock causes her memories of her previous life in another world as "The Shrouded Black Saintess" to resurface. Manipulated and discarded in this and her previous world, she tries to run away to a life for herself. However, Theodore, a mysterious, handsome man, suddenly appears before her. In dire straights, Maricia can't help but reach out and save him... What will happen to Maricia, who wants to live her life alone in peace, and Theodore, the man who wants to have her under a contractual engagement?!