Jessica Jung is an up and coming executive of the I'Park Mall in Seoul, South Korea. Although they are barely hanging by a thread, Jessica is determined to improve their sales for the 900 people whose lives depend on this mall. It's hard for her to think of a good idea to improve the lowest SM Mall in South Korea but maybe an end of the year promotion will get her in the mood to definitely do her best, and she's determined to get that opportunity.

Nichkhun Horvejkul has a tough life being the only child who can actually save his family's authentic Thai restaurant from bankruptcy. He's trying his best to help his father, working extra shifts, riding a bike instead of a car, and putting the restaurant before his own necessities, but his father insists that he should just ignore the restaurant and focus on a medical career. While juggling family issues, school, and a job Khun is desperate to get enough money to at least keep the restaurant open past Christmas, his favorite holiday.

Kim Hyoyeon, the loyal best friend and assistant to Jessica. She's spunky, enthusiastic, and loves her job as an assistant. If Jessica gets that promotion, the executive job will be passed down to her, which means more time for shopping! She loves Jess and she knows how vital she is to her work ethic but she can't help but feel a little bit of agony when her boss keeps pushing her down with commands and orders. Regardless she'll always have Jessica's back, but she's not sure if she'd do the same for her.

Lee Changmin can only wish the best for his girlfriend, Jessica. They've been dating for a while, and he has a close connection with their CEO which is how she got her executive position. Although work should bring them closer together, they've been farther apart, and hopefully the promotion challenge will help him and Jessica become closer again. But he's not so crazy about her new Santa Claus idea.