My Naughty Angel (2002)

Cheng Xiao Lu is a student in a training centre for tour guides. Playing tricks on others is a huge hobby of hers, and this gives the teachers a headache. Ding Jian, the newly arrived teacher, comes up with a number of punishments to stop Xiao Lu's doing, which results in hatred developing between them. After the training ends, Xiao Lu applies for a job in a travel agency, and Ding Jian gets hired by a travel agency that is competing with Xiao Lu's. Through their constant encounters at work, their previous hatred for each other gradually develops into mutual admiration. (Source: Chinese = Douban || Translation = MyDramaList)