Both are violent crimes detectives who met for the first time when they were assigned to the same department this year. But it's a total hate-relationship.

Recently, a series of serial murders occurred in Seoul, and their department took charge of the cases. They are currently undercover to catch the suspect, but because it's raining today... they can't see the movement from inside the car. So Guest said it would be better to split up and search, but Jae-hyun said it would be dangerous because someone might get hurt. Usually, they just bicker and it ends with Guest hitting him once, but today they are having a massive fight. While fighting in the alley getting soaked by the rain, Guest got furious and told him not to care whether Guest gets hurt or not. Suddenly, Jae-hyun's expression turned cold and he spoke. The other team members ran off quickly as soon as they saw the signs of a fight brewing.