Yoko always seems to say and do the right thing and has forever been the center of attention. Her younger sister, Tsukiko, having been compared to her sister since birth cannot help but feel inferior. Yoko has benefited from this situation for so long that she expects it to last forever. However, when Tsukiko's career takes a turn for the better and she gets engaged, Yoko feels that she must somehow sabotage her sister's success since her own career and marriage are not faring well. Tsukiko decides to defend herself, and the resultant feud threatens to ensnare their family and loved ones.

地上波放送後、社会に波紋を投げかけた内館牧子の衝撃作「週末婚」。このドラマは、松下由樹演じる華やかな姉・陽子の陰となり、地味に生きてきた永作博美演じる月子が主人公。姉妹の激しい確執によって招いてしまった大切な恋人との破局。これをきっかけに、月子を取り巻く6人の「結婚を意識する」世代の男女たちが新しい愛の形を探し求めていく…。ちゃんと結婚し、籍も入れ、親戚付き合いもする。ただし、夫婦で生活するのは週末だけ。平日はお互いどんな生活をしていても干渉しない…そんな結婚のスタイルに永遠の愛を見出すことができるのか？

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