- Female protagonist: Lin Xia, 28 years old, the ace detective of the crime team, a black belt in combat + a firearms master, with a fiery and straightforward personality, resolute and resolute in solving crimes, a bit of a "rough guy" in life, and full of complaining skills.
- Male protagonist: Shen Yan, 29 years old, has a doctorate in criminal psychology and a "sweeping monk" in the technical field. He is physically useless but has a high IQ. He is good at profiling, deciphering and "paper tactics". He has a sinister personality and a vicious tongue. He is always "bullied" by Lin Xia but enjoys it.
