Kinka 100-mai no Hanayome: Suterare Reijou wa, Soen ni Natteita Osananajimi ni Kyuukonsareru

Linde loses her fiancé to her cousin and is about to become the wife of a middle-aged man. So Barthes, a knight of an earl's family, proposes marriage to Linde in exchange for 100 gold pieces. He is a popular and handsome young man in the castle, but they have known each other since childhood, when they had a falling out. However, even after their reunion, he is still not very friendly and does not understand the intention of their courtship. Source: MU