I want to break off my twisted engagement, so I've decided to become a saint.

Carmia, a duke's daughter, was forced into an engagement with a prince for political reasons. Balancing academics with imperial concubine training, and for some reason disliked by the prince, she was reaching her limit. However, she accepts a proposal from a certain baron's daughter and is spurred into action. That proposal is: "To reach the pinnacle of sainthood." A story where a villainess and a heroine save each other.