In the distant land of Marei, a young noblewoman named Moerei—known as the Green Princess—lives in the palace, neglected and without influence. Her brother, the emperor, is weak-willed, while the Empress Dowager holds the real power, enforcing a cruel regime alongside a suspicious Taoist. Powerless and anxious about her brother’s fate and the suffering of the people, Moerei can only watch as things spiral out of control… until one day, a divine general—Huiying, envoy of the Heavenly Emperor—descends from the skies and enters the palace.