Moon Byulyi is an artistic genius working as the head of the creative team in Flanéur agency, an up and coming advertising agency spearheaded by another creative visionary, Kim Taeyeon. Her childhood was marred by abandonment and tragedy; she was left by her parents at an orphanage at a very young age, but she managed to nail a scholarship to the prestigious Seoul National University (SNU), where she met her long life best friend, Kim Yongsun a.k.a Solar, her mentor who takes her as a protege, Kim Taeyeon, and her seemingly love of her life, the shy, troubled artist, Jung Wheein. 

Despite a struggling childhood, Byulyi strives in her job. Soon she discovered and began mentoring her protege, the charming Kang Seulgi, who used to be her junior in SNU. Both Byulyi and Seulgi work hand in hand at Flanéur, bringing in big-name clients and winning every pitch with their impeccable ideas. 

One fateful night during the company's year-end party, the ever-introverted Byulyi sneak out the rooftop when she meets a strict-looking but remarkably beautiful women.. 

Little does Byulyi know, this fateful night becomes a catharsis of many dramas in her life..