Shortly after astrology predicts destruction to befall the Tang Dynasty, a coup d'état led by the crown prince Li's very own brother kills him and his wife and sons. Li's daughter, princess Yongning, manages to escape, but is soon declared dead alongside her family. Full of wrath, the princess swears to avenge them as she takes on the identity of a young man, Li Chang Ge, and moves to the Shou province to advance her goals. Li Chang Ge uses her wits to gain the trust of the Shou emperor and swiftly climbs the military ranks as a brilliant strategist. Captivatingly drawn, Song of the Long March portrays the feisty girl's adolescent journey toward countless unknown adventures, faithful comradeship, as well as formidable enmity awaiting her along the way.

The frank and straightforward wandering hero, Hu Zi, and the outwardly aloof yet kind-hearted noble man, Qi Xiaoxuan, become acquainted through conflict. From mutual disdain to becoming friends like "tiger and crane," they unite with a group of partners who are "adorably naive foodies" and "smiling with a sinister heart." In the end, they uncover the royal sorcerer's conspiracy, eliminate evil, and uphold justice in the human world.