Kim Taeyeon

Right after she was born, Taeyeon's parents were attacked and killed while she was in the new borns' room in the hospital by an unknown gang due to a conflict between them. She never experienced the love and kindness of her parents. She was always living by herself once she reached age 12 because she ran away from the mean woman who was forced to raise her by the government. She was a troublesome kid, failing school and playing pranks on authorities. This caused her to be disliked by the majority of her town. Her peers would ignore her because their parents told them to keep away from her, not only because of her reputation, but her parents' reputations as well. She was completely unknowing to this, and believed that everyone just hated her. She wanted to prove everyone wrong. She joined the SM Agency Academy after running away and did her best to become an agent. Her ultimate goal is to become the head of the agency, showing that she was worth something.

Jung Jessica:

Being both extremely talented and pretty, Jessica has always been a popular student in SM Agency Academy. However, her entire family was wiped out by an unknown group of people, thought to be the group that Taeyeon's parents were in league with. In complete angst from having her clan being killed along with her best friend/younger sister Krystal, she seeks revenge on the gang that killed them. She does not know Taeyeon's past though, so she does not think of her much. With her complicated past, she focuses on her goal solely and ignores the attention given to her by classmates and teachers. She tends to have a cold and serious personality.

Hwang Tiffany

As a younger kid, Tiffany was always teased and excluded for her bright red hair. She was brilliant in school, but was never acknowledged for it. She simply held her head up high and tried her best to do as well as she could. She was one of the fangirls for Jessica, holding her in high admiration. She was determined to get Jessica to notice her because if she, the most prestigious student in the academy, acknowledges her, then she would know that she was really talented. At first it was more of a competition to become noticed, but soon she started to fall for the Ice Princess's skill and coolness. She rivals Kwon Yuri for her affection.

Lee Sunny

Sunny is the heir to the SM Agency. Ever since she was a young child, she was forced to practice her skills in fighting, though she could never get herself to hurt anyone. This way, she would never get better at anything. She was marked as a failure and is almost at the point of being disowned. Discouraged and scolded by her uncle 24/7, her confidence level was always low. She does her best to but on a brave face everyday and try to be strong, but she could never change the way she felt inside. When she started to notice a young girl in the agency, things started to change for her as a 8 year old kid. She was none other than Kim Taeyeon, class clown and failure. Sunny was always an incredibly intelligent girl, so she noticed right away how coldly people would treat her. She was in fact the first person to acknowledge Taeyeon's potential. Taeyeon's determination and drive inspired Sunny to become more confident and never give up. Sunny's admiration grew to love as she became older and she is extremely bashful about it. She can't look Taeyeon in the eyes and can barely speak to her. Unfortunately this caused Taeyeon to (due to her being dense) ignore and think that Sunny was weird. Despite this and Taeyeon's obvious affection towards Tiffany, she keeps her crush to herself, hoping for the day that she might be able to confess.

Seo Joo-Hyun

Known as Seohyun to her friends, she is the youngest among them. She is talented, smart, and mature, and tends to keep her older peers in check. She's known as the "teacher's pet" at the school, though is extremely delicate and innocent.  She is a top student, falling only underneath Jessica and Sunny. While Seohyun is known to be a bright girl with an equally bright future, she works extremely hard every day, trying to cope with what she has. Her parents abondoned her as a child of 10, and she lived in an old, rundown little house ever since. Even though she was without parents, she wanted to prove that she didn't need assistance when it comes to being sucessful, making Seohyun a very independent girl. While this is true, she did feel a bit hopeless at times. If it weren't for a certain boy, always coming over with snacks and conversation, Seohyun would have given up on her hard work altogether. 

Kwon Yuri

Talented, confident, and beautiful, Yuri is a natural born leader in her generation in school. She is not considerably popular due to her high confidence, but she also has a dorky and funny personality around her friends. She, as one of the many fangirls, found Jessica admirable and cool. She constantly challenges Tiffany to competitions, trying to feel superior to a competitor of Jessica's affection. While the two are "rivals of love" she and Tiffany actually go way back as childhood friends. She was that confident friend who would always stick up for Tiffany when she was teased about her hair. They eventually grew apart with their separate activities and settled themselves as "friendly rivals."

Yuri's family were skilled fighters and agents, almost all being in either the military or fellow business.Her father is currently serving in a war.