Season 1
An intelligent young man, Jang Ho-woo is employed by the Taeil Accounting Firm. His excellent memory, sharp observational skills, and his innate sense for numbers lead him to be the firm's first high school graduate hire. Ho-woo soon uncovers a web of systemic corruption and injustice that can only be stopped by dismantling one of Korea's most prestigious accounting firms.
A High School Graduate Accountant
To find out the truth, Ho-woo decides to become an accountant and join Taeil Accounting Firm.
The Ugly Duckling Jang Ho-woo
Ho-woo refuses to join Seung-jo's team, while Hyung-woo tells Jang-hyun to add Ho-woo to his audit team.
The Proposal
Taeil Accounting is in chaos after the disclaimer of opinions is submitted, but Ho-woo comes up with a plan.
The Man Behind Every Plan
Ho-woo finds out who was really behind the report on Haebit Construction.
An Unexpected Turn Of Events
Upon seeing Ji-soo, both Ho-woo and Seung-jo get shocked. They need to find a way to prevent Soma Tech from being sent to bankruptcy court. Eventually, Seung-jo comes up with a way to save Soma Tech, stabbing his father in the back. Meanwhile, VP Ahn Seung-yeon returns to the firm, which disrupts the peace Je-kyun has been maintaining.
The Secret Plan
Ji-soo proposes Taeil Accounting to sell Cakebean, a dessert franchise. Seung-jo, who didn't want to be part of the sales deal, becomes the project manager after hearing Ji-soo was the client. While carrying out due diligence on Cakebean, Ho-woo learns that they've been cheating on their franchise stores. Meanwhile, Seung-jo looks into HK Private Equity and finds out the danger Ji-soo is putting herself into.
The Identity Of AN
Ho-woo decides to accept Sang-ah's offer to help. VP Han is furious with Ho-woo for ruining the sales of Cakebean, but he doesn't fire him. While looking into the identity of AN, Ho-woo finds out that VP Ahn Seung-yeon could've been involved in helping Sang Ah Group build up a slush fund.
Better Solution For Ilseong Formula
Ho-woo is sure that HK Private Equity already have known how much Sang-ah Group would bid since Han Je-kyun is the representative of Sang-ah Construction for the auction. Seung-jo tells Ji-soo that the fund operator of HK Private Equity is his father. Jang-hyun tells Hyung-woo that he can come by whenever he wants to speak his mind.
VP Han’s Big Plan
Lee Sung-joo finds out Ho-woo's relationship with Haebit Construction. Lee Bo-sung falls for Lee Sung-joo's trick and loses all of his shares.
What He Is Capable Of
Ho-woo finds out the man behind his parents' death. Jisan Bank ends up acquiring the problematic online loan company. VP Han spreads rumor regarding Jisan Bank's unstable management, causing chaos.
Jisan Bank At Risk
Jisan Bank is in trouble. To protect Jisan Bank from Je-kyun, Ho-woo, Yeon-ah, and Ji-soo go to see the president of Taeil and tell the truth about Je-kyun. Je-kyun announces a sudden personnel change to Ho-woo. Ji-soo says she will volunteer to be investigated by the prosecution to make Je-kyun take responsibility.
Finally Bringing Down Je-kyun
Seung-jo and Ho-woo successfully send Je-kyun to prison, but they soon hear that Je-kyun is out on pardon. Learning of Je-kyun’s plans to take over a bank in Korea, they try to protect small to mid-sized banks. Meanwhile, they receive help from an unexpected ally. Later on, everyone finds their lives moving on from the hectic struggles.