On wo Ada de Kaesareta Reijou no Kazoku ga Damatteiru Wake ga nai

Karin's wedding is just around the corner, and while she is enjoying a blissful meal with her family, her fiance Chris and his father suddenly inform her that the engagement is off. Though shaken by their unexpected declaration, Karin asks Chris for the reason, and he reveals that he has fallen for Mary, Karin's best friend. With her honor and dignity tarnished by Chris and his father's thoughtless actions, Karin plummets into despair. However, her brother asserts that they will give them "a taste of their own medicine." The Rhedsum family shall not be trifled with! Dive into a refreshing and elegant fantasy of nobility and revenge!

(Source: MangaPlaza)