Shiitagerare Oujo ni Tensei Shimashita ga, Ryuujin no Kago o Motsu Saikyou Kishi-sama ni Aisarete Shiawase desu

Princess Annette, who carries the memories of a painful married life from her previous existence, is reborn—but her circumstances in this life are just as cruel. Treated harshly by her own royal family, her future looks bleak. In the midst of this, she is suddenly betrothed to General Volker, a man who earned great merit in the war. But the marriage is no true reward—it is a scheme by the king to drive away those who are considered troublesome. Thus, Annette and Volker begin their married life, each pitying the other, thinking it must surely be an unwanted union… but what awaits them? A bittersweet, heart-melting romance fantasy of a tragic reincarnated princess and a straight-laced military man, where fate begins to turn through a political marriage. https://www.cmoa.jp/title/319633/