On assignment in a perilous city to inspect a Black Ops team and its notorious leader, an upstanding prosecutor steps into a deadly war between spies.

Through the course of their lives, a man and his first love are repeatedly separated from each other because of circumstances out of their control.

Gil Oh-so, an employee at a cleaning company, meets Jang Seon-gyul, the boss of the company. The two are diametric opposite when it comes to cleanliness. With the help of Oh-sol, Seon-gyul faces his mysophobia and falls in love with her.