Ikenie Daini Koujo no Konwaku: Hitojichi no Himegimi, Tekkoku de Chi no Saien to shite Daikangei wo Ukeru 

Claire was the unloved second princess of the Feitnam Empire, considered a failure by others. Under a peace treaty with the enemy Kingdom of Balatonia, she was sent to be a hostage and she went fully expecting to give up her life. But what awaited her was a warm reception as she was made the fiancée of the Crown Prince. She was recognized as someone with extraordinary intellect, and the people of the kingdom welcomed her as their future queen!