The alien Qiao Ran (played by Yan An) from Ling Ke comes to Earth to perform a mission. He purposefully integrates into the life of the Earth girl Xia Mingqi (played by Cheng Yazhao), protecting and encouraging her to regain her dream of dancing. Xia Mingqi falls for Qiao Ran's tenderness, but gradually discovers the strange phenomenon that Qiao Ran cannot be remembered by others, and that she seems to have forgotten him countless times...