Suterare Seijo wa Keiyaku Kekkon wo Mankitsuchuu. Koukai shiteru? Dakara Nani?

Michelle, head saint and fiancée to Crown Prince Alphonse, spends her days trying to fulfill unreasonable requests from nobles and working to maintain the protective barrier surrounding the land. She barely has time to eat or sleep and on top of that, she is the target of envy from those around her and is called "the cruel saint." A gaunt Michelle attends a party thrown by the prince, but what awaits her there is the calling off of her engagement and the termination of her role as head saint. When she hears the news, she shouts with joy in front of the smug prince! However, the king, concerned for the future of the country, tries to keep Michelle from leaving by ordering her to marry a man infamously known as "the lecherous marquess."

(Source: K Manga)