TF IV: the Aftertaste of Candy

Yun Yijie has always had a secret: He is not a real child. Through a bizarre time travel, he trapped his adult consciousness in this immature body of the same name. The past disappeared like smoke. He only remembered that he came from another world, but he could not find the answer to "Who am I?" Under the ignorant appearance of a child, he relied on fragmented memories and instincts to carefully explore the truth among strange families, until a familiar name passed through his mind - cold and deadly. But... Is it true time travel... Or is the memory confused...