Akuyaku Reijou wa Single Mother ni Narimashita Futago wo Hikitorimashitaga Koushaku-sama Kara no Dekiai wa Souteigai desu

A duchess named Estelle finds herself no longer engaged to the Crown Prince after being reincarnated as a villainess without realizing it. She chooses to live simply as a commoner and works at a restaurant in another country. Six years later, she manages the restaurant and raises the twin daughters of the previous owner, Coco and Mia. When Duke Frederick, claiming to be the twins' older brother, arrives, she pretends to be his lover to shield them from an inheritance conflict. This romantic fantasy follows the false engagement between Estelle and the cold-hearted duke, as she remains unaware of her reincarnation into a game.