本剧讲述的是爱上了同一个男人的3个单身母亲所展开的悬疑故事，小池在片中饰演的是养育着12岁女儿的单身妈妈兼职业女性·森下晴美，她将和涼（46）饰演的养育着15岁儿子的禁欲系健身教练小椋加奈子以及#岡本玲#（27）饰演的养育着双胞胎的温柔保育士藤宫茜一起围绕着丈夫所留下来的3亿日元继承权展开争斗。虽然是事实婚姻（未领结婚证但同居的生活），但和丈夫幸福生活的晴美在某天接到了警察打来的电话，说自己的丈夫被杀了。赶到了医院的她遇到了加奈子和茜，两人都说和自己的丈夫有着事实婚姻的关系。而根据丈夫的遗嘱，3人被引导合住在「单身母亲专用的合租房」。此外，丈夫还留下了“我将把3亿日元交给我所爱的「唯一的妻子」”这样的遗言。由此，3个女人围绕着作为最爱的妻子继承3亿日元的权利，展开了斗争……

單親媽媽森下晴美與女兒同住在「丈夫」天谷恭平的高級公寓。即使兩人並未登記，恭平也忙於工作只能偶爾來訪，晴美都不以為意，直到警方通知─她摯愛的丈夫慘遭殺害。晴美趕到醫院，這才發現恭平竟然還有另外兩名「妻子」！？她們的「丈夫」在遺言中要求三人一同居住，並要將鉅額遺產留給他最愛的一個妻子…

Harumi Morishita (Eiko Koike) lives with her husband Kyohei Amaya, but they have not officially registered their marriage. One day, she receives a phone call from that police that her husband has died. She goes to the hospital where her husband Kyohei Amaya was sent to. There, Harumi Morishita meets Kanako Ogura (Ryo) and Akane Fujimiya (Rei Okamoto), who both insist that Kyohei Amaya is their husband. Both Kanako Ogura and Akane Fujimiya have not registered their marriage like Harumi Morishita. A will was left behind by Kyohei Amaya. His will leads Harumi Morishita, Kanako Ogura and Akane Fujimiya to a single mother share house and states that he will leave 300 million yen to the only wife that he loved.