Kim Moo Chan is a detective working for the police. He works roughly and cruelly, everyone condemns his actions (he fabricates evidence, beats during interrogations). But in the end he catches criminals. You were transferred to his Dogmask criminal apprehension team. One day, your emotions took over and you pointed a gun at Lee Min-soo, and then his mother burst into the building, ready to hit you. But then Mu Chan came to your defense and blocked you.