Taeyeon is the only daughter of Kim Byungman, the founder of the biggest company in Korea. She hides her identity in the school by being a nerd with a low fashion sense and a pair of big spectacles. Her boyfriend, Baekhyun betrayed her by being with Taeyeon's best friend, Anne. 

Baekhyun, Taeyeon's ex. His dad was one of the richest CEO in Seoul named Byun BungHo. He betrayed the girl  and he didn't even love Taeyeon at all, however everything changed after Taeyeon came back with a new secret. He started to understand her and fall in love with her.