When Li Xia and her best friend enroll into the arts specialized Qian Chuan secondary school, they meet the legendary Fu Xiao Si and Lu Zhi Ang. Together, the group of youths officially begin their beautiful high school life. After graduation, the friends part with everyone going their separate ways, but everyone continues to fight for their dreams. However, they're all gradually changing and thus become doubtful about the origin of their friendship. A span of ten years makes them realize that other than memories, nothing can be eternal, but they learnt to love and grow.
The story is set in the Song dynasty and at the beginning of the Jurchen-ruled Jin dynasty's invasion of northern China. The first part revolves around the friendship of two men, Yang Tiexin and Guo Xiaotian, who became heroes in their own right as they fought the Jin invaders. The bond between the duo is so strong that they pledge to each other that their unborn children will become either be sworn siblings (if both are of the same sex) or a married couple (if they are of opposite sexes). The story focuses on the trials and tribulations of their sons after Guo Xiaotian's death and Yang Tiexin's disappearance.
Bai Luo Yin and Gu Hai are forced into each other's lives by their parents' marriage, but neither expects what their bond will become.