风头正劲的影帝郑直（信 饰）受邀出演电影《小城往事》的男主演，与急速走红的女星苏妮娜（钟欣桐 饰）上演一段小龙套追求白富美的爱情故事。在参演过程中，早已过惯大明星生活的郑直，对穷小子生活的把握和表现始终得不到好莱坞新晋女导演曼迪·吴（李小冉 饰）的满意。更为糟糕的是，他的表演竟屡被导演批评为不如群演。而一个叫作川子（余少群 饰）的群演，来剧组是为了找回他青梅竹马的恋人三妮。凭借着一张童年照与珍贵的记忆，川子认定当红女星苏妮娜就是他的三妮，小心呵护之余，他用自己的方式向已经有了高富帅男朋友Peter（袁成杰 饰）的苏妮娜表达着爱意。于是，四个不同背景的人在片场发生了一连串的争吵、矛盾，更有不少欢乐与热闹。

Top actor Zheng Zhi (Shin) and Nina (Gillian Chung) are starring together in a movie about a poor man romancing a rich girl. Filming isn't going so smoothly, however, as director Mandy (Li Xiaoran) keeps picking apart Zheng Zhi's acting. It turns out that Mandy and Zheng Zhi are actually former lovers, and the movie's plot is their own story. Meanwhile, Chuan Zi (Yu Shaoqun) joined the production as an extra in hopes of reuniting with Nina, whom he believes is his childhood sweetheart. Nina, however, already has a rich and handsome boyfriend.