Ada Choi
Chan Siu-Sang (Bobby Au-Yeung) is single and all alone, his old love Chu So Ngo married the doctor that treated her son and left the police force. Then he meets Wai Ying Zi (Ada Choi), a rookie police officer that is under Chan Sam Yuen Police Traffic Department unit. The two get off on the wrong foot due to misunderstandings. Wai Ying Zi who is eager to show off her skills seems to get into a lot of trouble. She is deemed reckless and rash. Later on Ying Zi joins Siu-Sang's CID unit which leads to the two bickering nonstop. After Siu-Sang saves Ying Zi's life on one their investigations she learns to respect him and the two become friends.