The roommate of an ordinary college student, Wang Mengqi, died mysteriously. When he died, a girl in red was found, but he was wrongly imprisoned. In order to clear his name and find out the true reason behind his roommate's death, the protagonist decided to escape from prison, then caught the girl and asked about the cause of his roommate's death. All doubts and clues revolve around the girl in red. In the process of pursuing the girl in red, the protagonist discovers that he does not actually exist in the world he has lived in for 19 years. . . . . . .