Love Is Not Selfish
A job to become the bodyguard of the Young Master of the Li's family so she could secretly protect the woman he loves in his absence. Although she found this idea crazy and ridiculous she still agreed to help him. She didn't turn down his offer because she was a witness of how much her cousin loved and yearned to be with the woman he loves.
With her qualifications and skills, she did not have a hard time winning Li Yifeng's admiration. Yifeng hired her but with the condition that she would work as an undercover agent in his mansion.
What better plan would any smart person have come with other than catching the enemies unaware?
As a maid, even an enemy will ignore her thinking that she was nothing. Even the most scheming person will let down his guard in the presence of the person she doesn't regard as a threat and Feng Shu's job was to fish out these hidden enemies.