After dying suddenly from overwork, she is reborn in the Underworld. From anime producer to cat demon girl, from revising scripts to saving the World Tree.
Her body is remade with the wrong gender, and she mistakes a marriage contract for a registration contract. If she doesn't break the contract within three months, her soul will be exiled to the River of Forgetfulness. The contract book is alive: it talks back, hits people, and turns its own pages. The Underworld's judge becomes her partner, and the Immortal Realm's heir becomes her teammate.
The power at her core accelerates her cultivation, and a halberd woven from demonic power and that core recognizes her as its master. But the elders of the Immortal Realm, who rely on slaughtering demon clans to prolong their lives, have their eyes on her power too.
Watering trees, breaking contracts, fighting, and getting bonked on the head by a book. Su Niannian's everyday life in the Underworld is far more exciting than working overtime to revise scripts.