Following the conquest of the Principality of Arita by the Skinia Empire, noble children are sent to the empire's academy for education. Upon reaching adulthood at 18, these youths are matched in arranged marriages to facilitate their integration into the imperial society. The countess Tiana finds herself betrothed to the esteemed knight Adele, a childhood companion with whom she has always clashed. Despite their lack of romantic sparks on their initial night together, Tiana believes their obligations are met. However, Adele continues to seek her out persistently. Is it merely a sense of duty that compels Adele, or could there be deeper motivations at play?