Xiao Li is a conscientious policewoman, and Xiao Bai is a petty thug who sells pirated discs. They both "work" on a bustling street but do not know each other. Xiao Bai, who has been involved with drugs, was once pursued by a drug trafficking group. In the subway station, with no way out, Xiao Bai offended Policewoman Xiao Li and secretly threw the key clue - a beeper - into Xiao Li's pocket. Xiao Li, who has just graduated from the police academy, lives with her father, Old Li, a retired policeman. Xiao Li was both angry and disgusted after being kissed by the little thug Xiao Bai. Things didn't end there because the beeper became the only reason for Xiao Bai to keep bothering Xiao Li.