Oukoku Monogatari

Purple-eyed Adarte, blue-eyed Adolte. One enveloped in light—the graceful son—and one shrouded in darkness—the prisoner. Even as their souls are drawn together, destiny would tear them apart. Elsewhere in the kingdom, a heroic king is served by an enigmatic aide from a faraway land. His path has torn him from his dearest kin and placed him in the halls of power—to what end...?
(Source: Yen Press)