Hiki Kagomori Ouji no Kenshin

To protect her homeland, Louise marries Arsenio, the first prince of a neighboring kingdom. But her husband’s constant unfaithfulness shatters their marriage, and she finds herself shunned even by her mother-in-law for failing to produce an heir. Lonely and heartbroken, Louise flees a humiliating scene at a royal ball. Only to encounter a mysterious young man in the Rose Palace. From their very first meeting, he confesses his love for her. Yet this stranger turns out to be none other than the kingdom’s long-missing second prince...! Original Webtoon: MechaComic