月子(菅野美穗 饰)和豹(泽村一树 饰)交往已久,两人早就决定携手步入婚礼的殿堂,月子在内心里格外期盼这一天的到来。哪知道自己的姐姐阳子(松下由树 饰)竟然怀上了豹的哥哥阿纯的孩子,为了顾全姐姐和豹的面子,月子只得忍痛解除了同豹的婚约。 离开了豹后,月子和自己的上司航一渐渐的走到了一起。航一的出现让月子逐渐的忘记了上一段恋情带给自己的伤痛。看到妹妹如此的幸福,阳子心生嫉妒,于是怂恿豹从航一的身边将月子抢回来,哪知道月子和航一的感情十分的坚定,阳子的作战计划失败了。月子不愿意重蹈姐姐的覆辙,于是向航一提出“周末婚”的提议,也就是两人只在周末以夫妻的名义生活在一起。This series follows the power struggles between an incredibly dysfunctional pair of sisters, starting with the elder sister breaking up the younger's wedding at the altar, then stealing away her fiance. Several years later, neither has forgiven the other, and they continue to undermine each other's homes and careers, using anyone and anything they can.