Set against the backdrop of the 1990s, this retro office comedy follows Hong Geum Bo, a no-nonsense financial regulator in her 30s who lives for her work. But when suspicious activity surfaces at a major securities firm, her career takes an unexpected turn. Tasked with uncovering the truth, Geum Bo goes undercover as a 20-year-old high school graduate, diving headfirst into an unfamiliar world of office politics, outdated tech, and hilarious culture clashes.
E1
While investigating Hanmin Investment & Securities, Hong Keum-bo faces a setback after meeting an informant — forcing her to go undercover.
E2
Disguised as a 20-year-old employee, Keum-bo cozies up to Go Bok-hee for intel — until her heart skips a beat when Shin Jung-woo arrives at work.
E3
While avoiding Jung-woo, Keum-bo continues investigating leads undercover. Meanwhile, she clashes with Bok-hee — causing tension at home.
E4
Despite preventing a disaster at work, Keum-bo faces imminent termination. While trying to secure her employment, she tries to track down "yehppee."
E5
A new arrival at the residence bothers Keum-bo. After learning of a spy, Chairman Kang orders an internal hunt — pushing Keum-bo to find "yehppee" first.
E6
To get closer to the truth about the slush fund, Keum-bo tries hard to win the top employee contest. Later, Jung-woo confronts her in a stuck elevator.
E7
Keum-bo witnesses a secret meeting between Albert Oh and a nefarious man from her past. Her suspicions grow as she closes in on what he's hiding.
E8
Keum-bo finally tracks down "yehppee," who won't cooperate. But when the IMF crisis hits Korea, her investigation takes a sudden turn.
E9
The brutal IMF financial crisis shakes the lives of four roommates. Meanwhile, Jung-woo begins a cutthroat restructuring of the company.
E10
Committed to her mission, Keum-bo moves forward with her plan to protect Hanmin employees — but Jung-woo keeps getting in her way.
E11
Keum-bo and Bok-hee bravely set their plan in motion to handle slush funds. Meanwhile, they find a puzzling online community.
E12
Now with a team assembled, Keum-bo launches an operation to go after corrupt company executives. The first target? Albert's father Oh Deok-gyu.