Jung SooJung is a second year university student in Seoul, who always had bad luck with men. She hoped to find the love of her life in university, but as summer is coming closer, she starts giving up on hope. That is, until she gets a letter from anonymous person. Just with that one letter, her love life is turned upside down. So, who wrote that letter?

Being the rebel she is, Krystal Jung made it her ultimate goal to seduce the new hot substitute teacher Mark Tuan, never mind a new threat coming her way, a.k.a. Kim Myungsoo. And so the game begins!

They met in their first music festival. In such a short time, they became close. Long after that unforgetable summer, they stayed in contact. But when the time came, the boy had to choose - to be a man and accept her feelings, or to be a good son and obey his parents. Krystal 

Do you ever feel like someone’s watching you? If so, does the nauseating feeling envelope you at dark and lonesome nights? Her mind was warning her, yet Krystal could never have imagined of was bound to come after her, of what was staying silent in the shadows.

It was a Prom night when he saw her again, the one who broke his heart all those years before.

   Krystal is an ordinary teenager. She sometimes behaves badly, gets in trouble and even hurts others. Her life rationally changes when two strangers intrude her kind-of-peaceful life, bringing her the truths that will hurt her deeply.  

Satisfaction was an unknown thing for Krystal Jung. Hence she never felt what mutual love means, or happiness to have a really special person hold your hand, she always felt left out from the teenage community. However, frustration, anger and mostly jealously were her every day companions. It didn’t help that her only good friend, Choi Jinri, recently found a boyfriend.