A damo is officially a tea servant, but secretly, she is a lowly ranked female detective. The main character, Chae Ok, is one such damo. She is skilled in swordplay and beautiful but not only does she have to fight crime, she has to fight discrimination against her social status as a servant woman and the fact that she is a woman. However, she was originally the daughter of a nobleman, but her father was accused of treason and killed. Shortly after, while they were escaping the pursuers, she was painfully separated from her brother. At such a young age, Chae Ok, becomes the servant girl of Hwang Bo Yun and his family. Hwang Bo has also faced discrimination against his social status because he is the son of a commoner mistress even though his father is a nobleman. As a result, he feels a connection between Chae Ok and Chae Ok in return has feelings for him as well. Hwang Bo becomes the commander of the police department Chae Ok works for. Little does she know that her brother grows up to become a rebel leader to fight the very societal injustice she faces every day. However, Chae Ok is a member of the police and so it's her duty to stop her brother who is breaking the law.
While nothing in joseon yeoheyeongsa damo ever comes close in class to shi mian mai fu, both series share a whole bunch of superficial, thematical and plot similarities. Over-dramatic plotline, stylish wuxia fight scenes and outlaw syndicates.