Hakushaku Fujin no Shutsuji

According to a lore, "A chimney sweep's presence at a wedding brings happiness," Jemima, the daughter of a chimney sweep, is invited to a nobleman's wedding. There she is asked by the Earl of Selborne for a kiss of luck. She has a crush on Lord Selborne, but he's just teasing her... But a few days later, he suddenly proposes to her. When she asks him, he says he wants a marriage of convenience because of his inheritance. But Lord Selborne, while saying that he will pay her, at the same time he starts hitting on her, saying that "You are the only one I want to marry" and "My beloved wife"...? Source: Harlequin