The “Yao Guan Hui” that governs monsters, in pursuit of some unspeakable secret, has accepted the Journey to the West scheme of the three great powers—Buddhist sect, Earth Immortals, and the Heavenly Court—and intends to use the expedition to trap every undercover agent and traitor lurking in the demon realm. A low‑rank little leopard, relying on his wits, sees through some of the Yao Guan Hui’s motives; to stay alive he devises every possible plan to slip out of the cave and save his skin, but by a twist of fate he ends up as the cave’s temporary de facto leader. With the Yao Guan Hui forbidding monsters from running amok, the leopard spirit, desperate to get out and keep his subordinates fed, reluctantly adopts the guise of a monster courier agency and sets off across the world.

He delivers the fetal‑birth spring to the Kingdom of Women and meets the destined true maiden, escorts a nine‑headed bird to Japan to rescue the Fusang demon realm, helps Zhu Bajie send a letter to Gao Cuilan… each encounter, each episode, is either humorous or sorrowful. The more he tries to avoid Tang Sanzang, the closer his courier routes bring him to the power centre of the demon world.

In the end, after learning the true nature of the Journey and the secret roles of Sun Wukong and the others, what choice will he make in this world where the four factions swirl like storm clouds?