Ordinary deliveryman Shen Changye turns out to be a mysterious figure who has lived for ten thousand years. Due to a bond of kindness from a hundred years ago, he meets Gu Zhiwei, the young lady of the Gu family. Together, through experiencing corporate troubles, the exploration of ancient ruins, and the mystery of longevity, they gradually build a deep affection. As the secrets of the Kunlun Gate are unveiled, Shen Changye, accompanied by Gu Zhiwei, unlocks his own seal and comprehends the true meaning of life and companionship. In the end, the two hand in hand return to the urban world, reaping happiness in ordinary life.