Because I, the True Saint, Was Banished, That Country Is Done For!

Saint Eliane's engagement is called off out of the blue by her fiancée, the crown prince Claude, who then banishes her from the kingdom. Fed up with Claude's incessant bullying and unfaithfulness, Eliane sets off to a neighboring kingdom in the hopes of starting a new life. It is then that she meets Nigel, a man of sincerity and an exact opposite of Claude... (Source: Kodansha)