30-year-old Kamata Rinko is single and a struggling scriptwriter. She has no boyfriend and keeps having night outs at drinking spots with her girlfriends Kaori and Koyuki. "If I become beautiful, a better guy will appear!" "If we grow to like each other, we can get married!" They will not stop talking about these hypothetical questions. Then a younger, handsome, golden-haired guy suddenly utters, "These "what if" women!" and the trio have to face the harsh reality that they are no longer girls. Rinko enters her 30s while still immature, seeking happiness and struggling with romance and work. 我必须恋爱的理由。讲真，你不是她，又怎能体会她心中的苦与乐？。如果是优雅餐厅高级大厨用不新鲜的鱼做的料理你会吃吗？。不是恨嫁，而是没钱。梦还是要有的，万一实现了呢？。做灰姑娘，别做睡美人。神似松坂桃李的男二，爱死你了。北京白日梦女。白日梦女的人间真实-平凡的恋爱就很好。白日梦女也可能会梦想成真的吧～。 八流编剧镰田伦子（吉高由里子 饰）、美甲师山川香（荣仓奈奈 饰）、某小餐馆老板女儿鸟居小雪（大岛优子 饰）是三个年过而立且相交多年的好朋友。过去的很长时间里她们都没有男朋友，三个人工作之余就凑在一起喝喝小酒，吹吹牛，奚落嘲笑为爱情竭力奔走的男男女女，却不知道原来在有意无意掩饰着各自情感上的空虚。新的一年里，她们的桃花期竟突然降临。伦子和萍水相逢的金发帅哥KEY（坂口健太郎 饰）相互厌恶，却有着意外的神展开。香重逢玩乐队的前男友阿凉（平冈佑太 饰）这次则变成对方的备胎。小雪与上班族丸井良男（田中圭 饰）陷入热恋，情愿成为对方的小三。 人过三十依然做着白日梦的大女孩，就此展开她们的恋爱征程……
