Dong Ju was an accountant of a leading company that took care of their secret funds. Dong Ju, who has experienced wealth and success, steps into the NTS following his father's death. Fully equipped with his brazen and crazy personality, he excels as a manager in Bureau Five. Oh Young and Seo Hye Young are his teammates in Bureau Five. Young and Dong Ju start things off with a bad start, but a special occasion brings the two together. Hye Young and Dong Ju have met before, and she has also had a connection with Young in the past. With her ability to act and with her intuition, Hye Young creates a good partnership with Dong Ju.

Dong Ju's journey to reveal the secrets behind his father's death continues. Tae Jun leads the NTS full of ambition. Dong Ju finds out that Tae Jun is related to his father's death and looks for additional evidence. Along with unlocking the secrets behind Dong Ju's father's death, Bureau Five continues to punish the tax evasion, secret funds, and corrupt trading of top officials in the country.