Belle Poupée no Spadari Konyaku: "Konomi ja Nai" to Iwareta Ningyou-hime, Gaman wo Yametara Ouji ga Deredere ni Natta. Jitsu ni Ui!

Duchess Laetitia, nicknamed “Belle Poupée” (the beautiful doll), has a fragile appearance, but her true nature is a generous and dashing heroine! She becomes engaged to Gilbert, the second prince, who is rumored to have some behavioral problems… The beautiful, heroic lady and the lonely, cursed red-eyed prince, this is a “reverse doting” love story between two people destined for each other!

(Source: MangaUP, translated)