Baek Shi-Yoon, a former secret operative, is a highly skilled human weapon. Concealing his history, he purchases a bar called “Neighborhood” and operates it as its proprietor. He forms close bonds with the bar’s regular patrons and empathizes with their struggles. During this time, Baek Shi-Yoon encounters a young man employed on a temporary basis, who aspires to join the police force. Baek Shi-Yoon takes the young man under his wing, training him as a covert agent, and together they combat malevolent forces.