Toshishita Shuuchaku Ouji wa Fuguu na Oujo o Itoshi Sugi Teru

Lia, a princess of a certain kingdom, grew up oppressed by her father and older sister. When she was blamed for their loss in a war with a neighboring country, Lia was scorned by her own people as "The wicked woman who ruined the nation." As compensation for the war, she was sent off to marry the king of the victorious country. There, she was treated like a slave, displayed as a spectacle. But in that moment of despair, Prince Senett of the Schwarz Kingdom suddenly arrived, cutting through the chaos. "I've come for you, my Princess." This is a frustrating, mismatched love story between the kind-hearted, ill-fated princess and a younger prince who dedicates a somewhat obsessive yandere love to her.

https://www.cmoa.jp/title/354220/