When a telecom executive develops face blindness, he mistakes his secretary for a wealthy heiress -- which she allows to get out of hand.
Do Min-Ik misinterprets his doctor and believes that an intimate night with his girlfriend would bring his heartbeat up. Later, he gets stuck in an elevator and when he does get out, his facial vision is temporarily restored. He uses this chance to see Gal-Hee's face and share a deep kiss.
When Jung Gal-Hee finds out that Do Min-Ik had given up his application to become CEO, she feels somewhat responsible and is upset. But he later reveals that he had convinced Ki Dae-Joo into running for the position. Eventually, Ki Dae-Joo becomes the CEO of T and T Mobile.
Jung Gal-Hee feels conflicted as her fellow secretaries start up a protest against the company leadership. Eventually, she sides with them and joins in on the fasting. Worried about Gal-Hee's health, Do Min-Ik gives up his CEO application to allow a negotiation table for the workers.
Jung Gal-Hee and Do Min-Ik take a day off work to spend some time together and go on a date, but Gal-Hee's siblings get in the way of their date plans. Eventually, they have no chance but to spend the night at the beach along with her siblings.
After the meeting, Jung Gal-Hee leaves her job and visits her sister's performance along with her brother. Meanwhile, Do Min-Ik regrets letting Gal-Hee go and plans on treating her to a meal. But seeing her with a man he can't recognize, he feels jealous and eventually tells her he loves her.
As Do Min-Ik faces trouble at the directorate's meeting, Jung Gal-Hee calls up Ki Dae-Joo for help. Do Min-Ik reveals his illness to the board and as the number of votes goes against Do Min-Ik, Ki Dae-Joo shows up at the meeting to cast his vote for Min-Ik, effectively putting off the final CEO voting.
Jung Gal-Hee struggles to come to terms with her dismissal and goes up to Do Min-Ik to beg him to forgive her. At first, his initial feelings of betrayal bring him to reject her apology but as he gears up for the directorate's meeting the next day, he allows her to act as his secretary for one day.
As Yi Eul-Wang fears the police furthering their investigation regarding Do Min-Ik's chauffeur, she decides to disband her group, Euldoguk to provide security for the other members. Meanwhile, Veronica Park and Do Min-Ik's supposed breakup leaves the mothers disappointed.
In an unexpected meal with Veronica Park, Do Min-Ik realizes that she's not the Veronica Park that he'd gone on a date with before. He later realizes that the Veronica Park he had loved was his own secretary pretending to be her and falls into deep disappointment.
Veronica Park and Jung Gal-Hee get into a car accident, in which they break a neck and arm respectively. Do Min-Ik receives news that both are injured but eventually chooses to visit his secretary, having decided that she's the one who he truly loves.
Do Min-Ik receives information that his chauffeur was the one to attack him and intrude Jung Gal-Hee’s house. Meanwhile, Jung Gal-Hee dressed up as Veronica Park is awaiting her date with Do Min-Ik until she gets disappointed over seeing him having decided on Veronica Park over her true self.
Do Min-Ik reveals to Ki Dae-Joo that he can’t decide between his feelings for his secretary and Veronica Park. Do Min-Ik continues to struggle with his divided feelings and eventually distances himself from Jung Gal-Hee and also decides to ask Veronica Park out.
Do Min-Ik reveals to Ki Dae-Joo that the woman he’s fallen in love with is Veronica Park. Ki Dae-Joo is shocked to hear that and tells Min-Ik to decide between her and Jung Gal-Hee. Do Min-Ik is torn between his feelings for the Veronica he knows and Jung Gal-Hee.
After an encounter with Do Min-Ik, Veronica Park finds out that Jung Gal-Hee had been impersonating her in front of Do Min-Ik all this time. As punishment, Veronica Park asks Jung Gal-Hee to continue pretending to be her as she herself hopes to develop her relationship with Ki Dae-Joo.
A cutter-knife is found in Gal-Hee’s home, which is linked to the burglary. Do Min-Ik remembers having seen the same knife in the hands of his chauffeur. His suspicion towards his chauffeur grows and as he’s temporarily able to see faces, he recognizes that of his chauffeur and goes to confront him.
When Gal-Hee returns home, she finds out that a burglar (Do Min-Ik’s chauffeur) intruded the house, in search of her laptop. Meanwhile, Do Min-Ik deals with his “breakup” with Veronica Park and while trying to get over it, he enjoys a home-cooked meal with Jung Gal-Hee.
After a tumultuous date at the jjimjilbang, Jung Gal-Hee and Do Min-Ik go see a movie, where they run into Ki Dae-Joo and the actual Veronica Park. Feeling even more conflicted, Jung Gal-Hee anticipates the 12 hours to pass as Do Min-Ik develops hard feelings for her.
Jung Gal-Hee, impersonating Veronica Park, carries on with her plan to “break up” with Do Min-Ik. However, Do Min-Ik proposes that they go on a 12-hour date before they finally say goodbye. Jung Gal-Hee lands in tricky situations where she is noticed by others who do recognize her face.
Veronica Park is pressured by her mother to marry Do Min-Ik and tries to come up with a new scenario to fake in front of Do Min-Ik. Jung Gal-Hee is determined to impersonate Veronica Park one last time to push the scenario that she's in love with another man.
Do Min-Ik reveals to his doctor that he was able to see faces during the general meeting. They assume that high blood pressure increases his chances of seeing faces He tries out physical activities and drinking alcohol to raise blood pressure, only to succeed later when he encounters Jung Gal-Hee.
After the exposing of footage showing other directors committing abuse of power, the general meeting concludes with the voting process. Do Min-Ik reveals to Gal-Hee that he wants to renew their contract. Do Min-Ik receives an invitation from his mother, to go meet up with the actual Veronica Park.
The stakeholders' general meeting opens, and Jung Gal-Hee and Do Min-Ik come up with a plan to reveal the abuse of power committed by other directors of the company. While up at the podium to make his case, Do Min-Ik suddenly recognizes faces of the people in the audience.
Heeding Gal-Hee’s advice, Do Min-Ik does not back down and rests his fate on the general meeting. At the general meeting, an unexpected guest, Veronica Park, arrives to Gal-Hee’s utter shock. At the moment, Do Min-Ik is once again able to see faces.
A video of Do Min-Ik assumedly beating up his chauffeur spreads throughout the directorate and many members use it as a pretext to contest Do’s resignation. As Do Min-Ik continues to struggle, Gal-Hee tries to persuade him not to easily back down and strive for the CEO position.
Min-Ik's chauffeur is seen stealing an object from Min-Ik's office. Despite a brief confrontation however, his identity and motive is not revealed. Min-Ik ends up in the hospital with a minor cut on his hand. Meanwhile, Min-Ik's doctor continues to search for clues to his illness.
Gal-Hee goes on the date with her boss, pretending to be Veronica Park. To Gal-Hee's surprise, Min-Ik is satisfied with the date. Veronica Park also meets Ki Dae-Joo as her date, whose motive is to hand her a filming proposal. Dae-Joo later asks approval from Min-Ik for his resignation.
Min Ik comes up with a way to start recognizing people without knowing their faces by compiling data of the physical features of each person. He is scheduled to go on a blind date with the famed movie titan, Veronica Park but misinformation leads to them arriving at different locations.
Gal Hee starts her work as secretary of Do Min Ik once again, but under better working conditions. Meanwhile, Min Ik decides to call off the investigation regarding his attack. Min Ik also decides to go on a blind date with the famed movie titan, Veronica Park.
Min-ik tries to convince Gal-hee to return as his secretary, offering her a permanent contract. Gal-hee takes time off to decide while Min-ik works with the police to discover who attacked him and why.
While suffering from face blindness, Min-ik realises that the only face he can see is Gal-hee's. Min-ik asks Gal-hee to help him navigate his new life and continue to be his secretary until the CEO election.
After getting fired, Gal-hee and the other secretaries are prepared to give Min-ik a piece of their minds. CEO Sim starts to turn board members against Min-ik. Min-ik is attacked and is dealt a devastating fall.
Jung Gal-hee is a diligent secretary to her boss Do Min-ik who is hoping to become CEO. Min-ik has one rule: he only keeps a secretary for one year before replacing her. Gal-hui works to convince him to renew her contract.
When a telecom executive develops face blindness, he mistakes his secretary for a wealthy heiress -- which she allows to get out of hand.
as Do Min-Ik
as Jung Gal-Hee
