Yin Shu and Si You are the two people in charge of the archives of the underworld, each overseeing one of the two great domains of life, death, and reincarnation. Yin Shu manages the records of the dead who return from the human world, while Si You oversees the reincarnation records of the animal kingdom. Whether they are human souls or the fates of animals, every destination in life and death is ultimately recorded in the mysterious Register of Youdu, divided into two clear and orderly sections.
