When Soojin receives the letter from BTS high, telling her that she has been accepted and will begin her first semester right after winter break, Soojin runs back home and tells her parents about it. Unfortunately for her, her parents would be going oversea to settle some business and thus unable to send her to school when the semester starts.

Soojin knows this is going to happen but she shows no sign of resentment, instead, she is grateful enough that at least her parents are free enough to listen to this big news of her.

Within a blink of an eye, the winter break is over.

The night before her first day in a new school, she decides to take a walk around her new school campus just to memorise the buildings of the school and make sure she wouldn’t feel nervous the next day.

What happens when she crosses an invisible border that leads to another world that she’s completely unaware of?

She's trapped... in a whole new world beyond the invisible borders of the walls... hidden from the human race... where deadly things exist. 

After being accepted into the grand, nationwide-known BTS High, Soojin is thrown into a twist of life-and-death events after she crosses the invisible border hidden in the school. She becomes the first human to discover the world in this century, and the Children of the Night. With vampires who want to her blood dry and dangerous loves tempting around her, will she be able to survive the many terrifying events to come?

Characters: