Captive Prince Rises To Sovereignty

Born the rightful royal heir, the male lead is robbed of his sacred identity token as a child and held as a laborer in a valley stable for 18 years. He displays staggering talent at the royal races, is framed and exiled by the fake heir, yet ultimately uncovers the 18-year deception, regrows his token, ascends the throne and rescues the poisoned female lead.