Ryuuou no Chouai: Hanayome wa Sougen ni Midare Saku

Give up the emperor's sister, the Princess Gyokuyou, in marriage. That is the condition for peace offered by the Northern Yan kingdom to the Eastern Hua empire. Tamayo is torn about leaving her homeland behind, until she meets the young man with jade-colored eyes who so forcefully courted her…

(Source: Chiffon Bunko, translated)