Betrothed to My Sister's Ex

With unmaintained red hair and shabby clothes, Marie, the baron's daughter, has been treated like a servant all her life. Count Granado, the country's richest man, who is said to be a difficult misogynist, falls in love with her at first sight. However, due to a misunderstanding, Count Granado proposes to her sister Anastasia, who looks like a princess, instead of the ragged Marie. (from manga)

Source: Anime News Network Encyclopedia