- Song Xian (attack): Captain of the Criminal Investigation Detachment of the Municipal Public Security Bureau. He is unruly and flamboyant, full of hormones, and decisive in handling cases, but he is repeatedly defeated in front of Qin Yan. The heir to the top wealthy Song family, he left the business empire alone and insisted on living on the front line.
- Qin Yan (accepted): Chief of the Forensic Medicine Department of the Municipal Public Security Bureau. Cold and ascetic, there is paranoia and sharpness hidden under the white coat. His fingertips can dissect corpses and can accurately poke Song Xian's pain points. The heir to the top wealthy Qin family plunged into the cold autopsy room.
- Relationship: Fa grew up in the same household, lived in the opposite door, and his parents were family friends. They have been in the control group of "other people's children" since they were young. They have been fighting all the way up to adulthood, verbally attacking each other, but physically being very honest.
Philosophy: They have similar family backgrounds and grew up in the same neighborhood. Song Xian is the unruly criminal investigation captain, while Qin Yan is the cold-blooded forensic elite. The two have been in tit-for-tat since childhood, competing in everything, with one hot and one cold personality, and a naturally incompatible temperament. There was a tit-for-tat confrontation at the crime scene, evidence was wrapped up in suspicion, and there was no room for compromise between words and intentions; they were secretly concerned and longing for each other, but they used stubbornness and alienation to disguise their feelings. One goes into danger to chase the murderer and solve the case, while the other sticks to the anatomy table to restore the truth. They walk side by side in the mist of the unsolved case. They are deeply bound by fate in the perennial contest. They use restraint to hide their deep feelings and use confrontation to spend the rest of their lives. While competing with each other, they redeem each other and run in both directions.