Betrothed to Prince Asbert of the great kingdom of Noston, Claire is shocked when the engagement is suddenly annulled. More than that, the new consort to the throne is none other than her sister, Charlotte! As the daughter of the now disgraced duke and scorned as a villainess, Claire leaves everything she knows and sets out on a journey to find her true self. But wait, isn't that's the plot of the game "Upstart ETERNAL LOVE" on its hardest difficult setting...? Saki Ichibu is a light novel author who has released several titles on the Japanese self-publishing site Shôsetsuka ni Narou, including Formerly, the Fallen Daughter of the Duke, and numerous other isekai stories. Creating the art to bring Ichibu's story to manga form is Ushio Shirotori, also known for Ayashi Kotogatari.