Tensei Oujo wa Ai Yori Ryouchi ga Hoshii Node Seiryaku Kekkon wo Kiboushimasu!

Princess Feris is actually a Japanese woman, reincarnated into the world of her favorite strategy simulation game. She is known as the "Warrior Princess," taking advantage of the game knowledge from her previous life. However, as soon as the war is over, she is ordered by the king to marry. She is competing with her sister to find a consort, and depending on her partner, she may not be able to stay involved in national politics....... But she'd rather build up her kingdom over getting married! While she is calculating which political marriage can give her the most territory, Orpheed, a sorcerer who is one of her most trusted subordinates and a potential fiancée, unexpectedly confesses his love to her―!?

(Source: Iris NEO, translated)