Your Highness, The Woman You Abandoned is The True Saint.

In a small country on a certain continent, Lamberth, there is a being known as a "Saint" who possesses strong healing powers and brings prosperity to the country. Irene, the daughter of a marquis who was engaged to Maynard, the first prince of Lamberth, is suddenly informed by Maynard that he is breaking off their engagement. The previous Saint has died, and it is necessary to decide on the next Saint as soon as possible. The two were originally engaged for political reasons, but Irene is irritated by Maynard's cold attitude. However, at the Saint selection ceremony, Irene is chosen as the true Saint... (Source: Natalie, translated)

It is mid-spring in the country of Brior. Olivia, a duchess, pretends to be a fool under the order of her fiancé, the crown prince, Alan, and suddenly, he tells her that their engagement has been broken off. Olivia was stunned, but she was even more confused when the second prince, Cyrus, suddenly appeared in front of a large audience and asked her to marry him.