露易斯和洛特是一对双胞胎姐妹。由于父母离婚,她们从出生就分开生活,直到在夏令营中相逢后,两人才相认。为了见一下素未谋面的爸爸妈妈,两人交换身份到了对方家中。在感受到不同的亲情后,盼望一家团圆的二人又计划撮合父母复婚。可是这时,不知情的爸爸正打算与另一位女子结婚。情急之下,两人除了想尽一切办法让父母见面,还要与父母的新娘斗智斗勇…… 本片改编自德国小说家、剧作家埃里希•卡斯特纳(1899-1974)的同名经典之作。When Louise and Lotte meet they quickly realize that they are twins separated after birth. They switch identities, meet their unknown parent, respectively, and try to find out about the divorce. Bad news: Dad plans to marry another woman.