Hoshifuru Oukoku no Nina

Nina never imagined she would be at the center of a royal deception. She's had a rough start in life as an orphan in the castle town of Fortna. But when Prince Azure notices that her deep blue eyes look the same as the late Princess Alisha's, he ordains that she takes her place and marry the Prince of Galgada. Despite this uncertain fate, she finds joy in knowing someone finally needs her.