英俊潇洒的栗正（贺军翔 饰）在家姐栗影（高菲 饰）的“真爱俱乐部”担任“真爱调查员”，出面接触委托人的未婚妻或者女友，为这些多疑男人的婚姻大事把脉，栗正的这份工作做起来得心应手，同时倍感疲惫。栗影的俱乐部接待了一位新的委托人——钻石王老五萧枫（吴大维 饰），栗影芳心大动，指派弟弟再次出马，令其勾引萧枫的未婚妻菲尔（林心如 饰），好促成自己和萧枫。任心理咨询师的菲儿颇有主见，使栗正大感棋逢对手，数次接触之后，栗正竟对菲儿暗生情愫。另一方面，栗影以调查做借口介入萧枫的生活，但随着四人的了解渐渐加深，栗家姐弟发现事情并没有那么简单……

Li Zheng and Li Ying are two brothers the owners of a dating agency called "True Love Club". The business is going very well, but everything changed when Xiao Feng is passed by a sweet love, who is interested in the agency to prove the relationship with their supposed "future wife", the beautiful psychiatrist Fei. What they do not know is that this regular case ends up in an unexpected and fun mess.