When Tang Seng and his disciples passed by the Kingdom of Daughters for Buddhist scriptures, the place that Tang Seng missed deeply in his heart. A sentence about "if there is an afterlife" created a thousand-year bond between the two of them. Under the arrangement of Lord Tathagata, Tang Seng was reincarnated as a human being, but the fate of his previous life was over. Since many demons and ghosts were eliminated and collected on the way to seek scriptures, they or their descendants would be detrimental to the reincarnated Tang Seng in this life, so the four disciples were also reincarnated to secretly protect them.
