A mysterious monster inn hides quietly within the bustling city, accessible only to those destined to visit. Shouguan Feiye, a monster hunter, becomes trapped in the inn for a thousand years, neither aging nor dying, after being cursed by the vengeful spirits of the monsters he has slain. To break the curse, he is forced to bring back Dongfang Zhaobai, the former innkeeper who has lost his memory. Meanwhile, other guests with unresolved ties to the two gradually arrive at the inn, each carrying lingering regrets or unfinished emotional burdens. As they help these guests release their obsessions, Shouguan Feiye rediscovers long-lost human emotions, and Dongfang gradually softens his rigid view of monsters. In the end, the two join forces to defeat the mastermind Monster King, restoring peace to the world, resolving a centuries-old misunderstanding between them, and falling in love with each other once again through their shared journey.