该剧讲述了曾经拥有完美一切，长大后却逆变无人关注的“龙套女“，与送走年少时期“矮挫胖”蜕变时尚精英的“高冷男”之间阴差阳错“守护初恋”的爱情故事。

白皓宇（盛一伦 饰）出国念书归来，想要见一见自己曾经的青梅竹马慧珍（迪丽热巴 饰）。曾经，慧珍是前途无量的美少女，但如今，她不过是一介毫不起眼的超市理货员。为了不让白皓宇失望，慧珍找到了自己的白富美闺蜜夏乔（李溪芮 饰），求她假扮自己去和白皓宇见面，哪知道夏乔假戏真做，对白皓宇动了芳心。 　　慧珍找到了一份杂志社的新工作，让她没有想到的是，自己的上司竟然正是白皓宇，一开始，白皓宇十分看不上大大咧咧傻里傻气的慧珍，但随着时间的推移，白皓宇渐渐在慧珍身上看到了过去的影子，对夏乔和慧珍的真实身份产生了怀疑。与此同时，记者林一木（张彬彬 饰）亦对慧珍展开了热烈的追求。

A joint work of three debuting directors. It is a film about former rock musicians, members of a banned rock band. The friends were forced to replace their ideals by settled family lives and ordinary jobs. When their former lead singer has to go to hospital for therapy, they get an unexpected opportunity to play together again and recall the old times. The day when all needs to be arranged for the performance is full of small lies, compromises, and morally doubtful decisions.

A joint work of three debuting directors. It is a film about former rock musicians, members of a banned rock band. The friends were forced to replace their ideals by settled family lives and ordinary jobs. When their former lead singer has to go to hospital for therapy, they get an unexpected opportunity to play together again and recall the old times. The day when all needs to be arranged for the performance is full of small lies, compromises, and morally doubtful decisions.

南宋时期，良家女子李慧娘（胡芝风 饰）因抨击时弊被奸相贾似道（许鸿良 饰）杀害，含冤九泉之下的李慧娘阴魂不散，化作幽灵飘回人间，报仇雪恨。贾似道对太学生裴舜卿（詹国治 饰）恨之入骨，设计骗其进贾府，伺机谋害。掌握生死大权的明镜判官（刘传海 饰）生性爱憎分明，让在阴曹地府的李慧娘暂回人间搭救裴舜卿，慧娘手执判官相赠的阴阳扇，来到囚禁裴舜卿的房内，裴见李深夜探访，疑心重重。慧娘道出原委，舜卿方知慧娘是一大情大义之人，并不知道眼前的美人是个鬼魂，心生怜悯与爱意。光阴恨短，李慧娘趁雄鸡报晓之前离开了裴舜卿。回到阴间，冥冥之中感觉三更时分裴舜卿有杀身之祸......

南宋时期，良家女子李慧娘（胡芝风 饰）因抨击时弊被奸相贾似道（许鸿良 饰）杀害，含冤九泉之下的李慧娘阴魂不散，化作幽灵飘回人间，报仇雪恨。贾似道对太学生裴舜卿（詹国治 饰）恨之入骨，设计骗其进贾府，伺机谋害。掌握生死大权的明镜判官（刘传海 饰）生性爱憎分明，让在阴曹地府的李慧娘暂回人间搭救裴舜卿，慧娘手执判官相赠的阴阳扇，来到囚禁裴舜卿的房内，裴见李深夜探访，疑心重重。慧娘道出原委，舜卿方知慧娘是一大情大义之人，并不知道眼前的美人是个鬼魂，心生怜悯与爱意。光阴恨短，李慧娘趁雄鸡报晓之前离开了裴舜卿。回到阴间，冥冥之中感觉三更时分裴舜卿有杀身之祸......

南宋末年，国难之时，奸相贾似道（胡国美饰）携歌妓李慧娘（吴素英饰）游湖玩乐，少年书生裴舜卿（吴凤花饰）拦船痛斥，李慧娘因赞其“美哉少年”，惨被贾似道杀害。李慧娘得判官（薛巧萍饰）允许重返人间，放走被贾所囚的裴舜卿，火烧半闲堂，谱写一曲“撼天地，为民疾”的伟大女性的颂歌。

南宋末年，国难之时，奸相贾似道（胡国美饰）携歌妓李慧娘（吴素英饰）游湖玩乐，少年书生裴舜卿（吴凤花饰）拦船痛斥，李慧娘因赞其“美哉少年”，惨被贾似道杀害。李慧娘得判官（薛巧萍饰）允许重返人间，放走被贾所囚的裴舜卿，火烧半闲堂，谱写一曲“撼天地，为民疾”的伟大女性的颂歌。