“镜中人”阿B，是一个活在镜中世界的演员，她的任务就是扮演现实世界大红的镜像。直到有一天，她发现，如果大红死了，她也会因此消失，所以她不顾一切冲出了镜面，来到现实世界，扮演起大红，并试图挽回大红的男友，以阻止大红的自杀。然而，她却在不知不觉中，爱上了这个熟悉而又陌生的男人。“B” is an actress who lives in the “mirror world”. Her job is to perform as the mirroring of “Da Hong”, who lives in the “real world” and has the same appearance of her. One day, B accidentally finds out that if “Da Hong” dies, she would also disappear, forever. Desperately and daredevil, “B” rushes out of the mirror and successfully goes to the real world. Only if she can turn the boyfriend of Da Hong’s heart back, can she prevent Da Hong’s suicide. However, as she conducting this mission and playing the role of “Da Hong” in the real world, she falls in love with this strange yet familiar man.