Seijo ni Naritai Wake de wa Arimasen ga: Henkyou kara Kita Inaka Musume nanoni Ou Taishi-hi Kouho ni Erabarete Shimaimashita?!

One day, the daily life of Lily, a girl who has lived a carefree life on the frontier, changes completely. Her parents were transferred to a fortress in the east where the situation is unstable, and were forced to leave their young daughter in the care of relatives, the Earl Tinam family, who live in the royal capital. Lily desperately wants to return to her family, so she works to improve herself in the royal capital in the hopes of being assigned to the eastern fortress. However, contrary to her wishes, she is chosen as a saint candidate but becomes the object of the Crown Prince's affection?! Moreover, at this time, the kingdom's survival is in danger... Source: MU