He Yan, the eldest daughter of the He family, is forced to disguise herself as heir He Rufei in order to protect her family's title. In her youth at Xianchang Academy, she meets the gifted Xiao Jue, but later abandons scholarly life to forge her own destiny on the battlefield. Betrayed by her family, He Yan survives and reinvents herself as He Yan. Disguised as a man, she enlists in the Yezhou army to reclaim her rightful legacy. Her path crosses with the noble Chu Zhao and reunites her with Xiao Jue, who is suspicious of her. She proves her worth by topping the military exams and surviving deadly trials — from the Sun family incident and Princess Jiyang affair to the defense of Rundu City — as rivalry with Xiao Jue evolves into mutual trust and affection forged through war.