Saet-Byul took a day off to pay respect to her father's death anniversary, while Dae Hyun is frustrated at not meeting Yeon Joo's family celebrating her father's birthday.
His girlfriend comes from a wealthy family, and for two years, she hasn't introduced him to her parents. He stops working at the company to start his own business but still not enough to compensate for his family background.
Seung Joon is the head of the corporate office where Dae Hyun previously worked. He is the direct manager of Yeon Joo and the only rival to their relationship.
Yeon Joo heard about a young and pretty part-timer in the convenience store from her colleagues. She advises Dae Hyun to change and hire a new part-timer instead. To confirm her suspicions, she went and checked out. By the time she visited, Geum Bi, in a rugged look, met her. Yeon Joo then calmed down and thought no need to worry about any girl that would get Dae Hyun's attention.
Saet-Byul, on the other hand, is supporting her younger sister Eun Byul, who is hanging out with the wrong crowd. She hides from Saet-Byul about her late-night hangouts.
Dae Hyun invited Yeon Joo for a date and visited a newly-renovated bar where young girls hang out for drinks. Saet-Byul and her friends dined in and ordered as well. Yeon Joo went to the bathroom and encountered the brat-mean girls. They harassed and asked her to cash out money for them. She was too afraid to get beaten by them.
At the same moment, Saet-Byul felt the urge to go to the bathroom. She was stopped at the door to get inside. She found out that the mean girls are harassing someone (Yeon Joo). In her attempt to use the bathroom, she fought with them and gave Yeon Joo's safety.
Dae Hyun rushed to the bathroom and saw Yeon Joo with Saet-Byul. He thought that Saet-Byul was in her war-freaked behavior again. He grabbed Yeon Joo's hand and left Saet-Byul, which made her frustrated with his reaction.
He then agreed to replace her part-timer as per Yeon Joo's request. But to his surprise, three men who stole from his store came up and paid their dues. They got scared after Saet-Byul beat them up. Her good friends showed up and told him how Saet-Byul saved his girlfriend at the bathroom bar incident. He realized that Saet-Byul worked hard for the store amidst trying to protect the people around him.
At the advertising company where Yeon Joo works, she held a team meeting for their partners. Saet-Byul works as a sales promoter and she is known as the "sales queen" for her good performance. Her manager asked for Saet-Byul to attend the meeting and double her salary for the day. They requested Saet-Byul's inspirational speech in front of Yeon Joo's whole team. Yeon Joo met her and tried to hide her disappointment.
The report from the head office arrived. Dae Hyun's family found out Saet-Byul is the "best employee of the month." In her efforts, the sales went up to threefolds from its previous month.
Dae Hyun decided to make Saet-Byul a permanent employee and surprised her with a bouquet. To appease her, Dae Hyun agreed to give Saet-Byul a piggyback ride. As they went laughing and enjoyed the moment, Yeon Joo arrived at the store and saw what they were doing.
