Saihôshi, The Guardian

The spoiled Prince Anel must travel without military escort to a neighboring kingdom where tensions run high. Sastre, an honorable Guardian, is brought in to be Anel's only protection for the journey. Anel is enchanted by his noble bodyguard, but Sastre becomes more interested in Kaleth, the spirited servant and lover of Prince Anel. Kaleth is forced to disguise himself as the prince to be a decoy for his enemies. Sastre duty is to protect Prince Anel, but in his heart he'd rather keep the decoy safe from harm. If the Guardian Sastre wants to avoid a death sentence he must rescue Prince Anel, defeat his rival Riot, and prevail against a rogue Guardian. That leaves little time to protect Anel's decoy, who he's falling in love with.