Ikenie Akujo no Shiroi Kekkon: Mezametara 8-nengo, Katsute wa Goei Datta Koushaku-sama no Dekiai ni Naremasen!

Overview

Ninette, a baroness, is known as a wicked woman because of her constitution which attracts the opposite sex. Her stepmother and stepbrother took over over the family mansion, and forced her out to live in a hut, with only a young boy, Till, to act as her bodyguard. One day, Ninette is framed by her stepbrother and offered up as a living sacrifice. But it turns out to be an opportunity for her to gain great power. When she returns to the town, eight years have somehow passed...... and she decides she will live her life alone. But Till, who was once a boy, has grown up, and he still harbors feelings for Ninette, even after she suddenly disappeared. Now he offers her a contract marriage. (Source: Comic Brise, translated)

Source: AniList