A story about the youth of this millennium follows a group of students who encounter ups and downs in the marathon of life. Ma Tian who comes from a well-off family and his goody-two-shoes neighbor An Ran transferred to an ordinary high school during their senior year; where they meet different kinds of people — Lao Gou (‘Old Dog’), Da Lijiao, Mimi, Da Zui (‘Big Mouth’) and Song Jie.