Mary Doe (メアリー=ド)

Alellia, who has had her engagement broken off, is past the marriageable age, and is known behind her back as the "domineering female supervisor." She spends her days performing her duties as the right-hand woman of Marquess Istilia Wegmund, "the cold-hearted prime minister." One day, while performing her duties, the Prime Minister asks her to marry him. Rumor has it that the Prime Minister is in love with another woman. Alellia accepts the engagement, believing that she is being asked to enter into a contractual marriage. A newly-married life with the cold-hearted prime minister begins...!

Once a commoner, Wellmy Ernest ascended to nobility when her mother married an earl. She tormented her same-age half-sister at home and school, stole her heirship and fiancé, and finally sold her off to the allegedly cruel Lord of Magic. It's not like her plain, meek sister could oppose. Wellmy got everything she wanted. One day, Wellmy receives an invitation to a late-night soiree from the Lord of Magic, likely to announce her sister as his fiancée. Wellmy attends with her mother and father, but what awaits them isn't the brilliant banquet they were expecting... it's a tribunal condemning them for their abuse of Wellmy's sister. Which means everything has gone just as Wellmy planned... Source: Manga UP! Global