When Seo Eun Young's fiance, Kang Jung Woo, leaves her alone and pregnant, she manages to get on with her life. Just as she has a chance to find happiness with Kang Hyung Woo, Jung Woo returns to complicate everything.

Cha Gong-chan was able to enter the top private high school in the affluent Gangnam District, Myoung-mun High, because of his soccer skills. But when he quits the sport, he finds himself an outcast and starts cutting class. One day, a beautiful new girl transfers to the school, and when she walks into his class, Gong-chan falls for her instantly. He is finally enthusiastic about going to school, but the school administrator informs him that he will be expelled if he misses one more day. Gong-chan vows that he won't give up on either his school life or his love.

After going through training to overcome bullying, a high school teenager who has had problems with his life and his relationships in school must face a bully on the first day school.

Celebrity guests are split into two teams to compete in various contests. One guest, known only to himself, is designated the "X-Man", and does his best to cause his team to lose the contests. At the end, all guests try to determine the X-Man's identity.