At Sundeok's school, there is an old bachelor teacher, Kim Taenam. One day, he finds out about the Red Book from his local bookstore. And, the book spreads to the school as well. For her friends who want to read more of the Red Book, Sundeok decides to write the book on her own.

Set in the microcosm of a school mirroring a jungle-like society, the story centers around one boy's desperate struggle for survival. Lee Ji Hoon is set to play an up-and-coming tough guy within the bullying circle of an elite high school in Busan, who's got a secret in his past and an unexpected charm.

Man-Sik is a single father who raises his 7-years-old daughter Ye-Na alone. He has yet to register her birth, because he wants her birth certificate to be the same as the other kids, which is to have a mother and father. In order to do so, he offers a deal to a woman from Vietnam: he will pay her 20 million won to put her name on a marriage certificate as his wife and Ye-Na's birth certificate as her mother. She declines the offer and Man-Sik becomes devastated. Mi-Hee then appears