Hwangtaejaui Yakonnyeo

Palace maid Viola Vilvaura was in the wrong place at the wrong time when she overheard Crown Prince Adrian Aphensen's secret. It turns out his fiancée was really his bodyguard in disguise! Not only that, but the bodyguard has disappeared, leaving the prince with no one to marry! Now that she's learned this secret, the only way for Viola to save her neck is to take on the role of Etienne, the crown prince's fiancée, and become the new princess. But how long will they be able to keep up the act?
(Source: Tapas)