The love story between virtual idol Rainbow and music producer Xiao Kai. Xiao Kai is a music producer who makes music for a virtual idol, Rainbow. He has a cold personality and loves to be alone. Music is everything to him and can’t live without it. Rainbow is a virtual idol who does not exist in reality but one day, she becomes human. She followed Xiao Kai to run away from the public and her manager. The two gradually fall in love with each other during their escape journey, but both of them encounter difficulties. Xiao Kai is afraid that one day, Rainbow disappears because they're not from the same dimension.