Jin Goo discovers the truth abot Park Ha Sun's family background.

In the 12th episode of the KBS drama "Advertisement Genius Lee Tae Baek" that aired March 12, Lee Tae Baek (Jin Goo) discovers that Baek Ji Yoon (Park Ha Sun), who he thought is an orphan, is actually a secret biological daughter of the BK Group president.

President Baek (Jang Yong) of BK Group calls Mr. Ma (Go Chang Suk) into his office to tell him that Baek Ji Yoon is his biological daughter. He also tells Mr. Ma, "Fire her. If you don't do so, you and everybody else working for the company will have a hard time making a living." When Mr. Ma returns to his office, he tries to fire Baek Ji Yoon but she tells him, "The blood of President Baek runs in my veins but I never thought of him as my father. I was to live as the daughter of my mother, who used to be a copywriter."

Lee Tae Baek sees the two having a serious discussion and asks about what is going on but both of them remain silent. Baek Ji Yoon tells him to wait and Lee Tae Baek says he will wait if she tells him to. Touched, Baek Ji Yoon kisses him on the cheek.

Mr. Ma and Baek Ji Yoon decides to stand up for their company even with the threat of President Baek remaining at the back of their minds. Soon after, the Giant Ad Company decides to enter a competition to promote traditional Korean food. After spending countless hours, Baek Ji Yoon comes up with an idea for a design that qualifies in the first round, 50 to 1.

However, the same exact design begins to show up in the internet. The Giant Ad Company gets involved in a lawsuit for plagiarizing. Baek Ji Yoon figures out who had created this mess and goes to his office right away. Ignoring everything Baek Ji Yoon says to him, President Baek orders her to marry Eddie Kang (Jo Hyun Jae) and says, "A father doesn't even have that kind of right?"

Lee Tae Baek was following Baek Ji Yoon and ends up hearing the whole conversation. Lee Tae Baek is overcome with a mix of emotions and is too shocked to do anything.