高梨春子（深津绘理 饰）是一位性格十分开朗活泼的女性，虽然已经三十岁了，但无论是外表还是言谈举止，春子都给人一种充满了年轻活力的感觉。在生日那一天，春子口误将自己的年龄说成了二十五岁，爱面子的她没有及时纠正这个错误。在宴会上，春子邂逅了名为柏仓一郎（冈田淮一 饰）的男子，两人因为误会而产生了一些不愉快，之后，一郎烂醉，春子无法坐视不管，于是带着一郎来到酒店。 一来二去之间，春子和一郎之间产生了真挚的感情，但一郎始终一位春子只有二十五岁，而春子总是无法找到合适的机会来澄清这一误会。最终，得知真相的一郎大度的接受了春子的年龄，但他告诉春子，自己是家中的独自，如果两人结婚，那么春子就要和他的母亲和姐姐住在同一屋檐下。
Plot Summary:Haruko Takanashi is 30 years old and works at a radio station. She is approaching middle management where good looks alone aren't enough. She isn't very romantic so she devotes herself to work and play and suddenly finds herself alone. Just when she has given up on romance she meets a man at a party to which she was taken by a subordinate at work. He is 25-year-old Ichiro Kashiwakura and is nothing out of the ordinary. They start a relationship. One day, out of the blue, Ichiro ardently proposes to Haruko. Realizing that he really loves her, Haruko says yes and they get married, but she still hasn't told him her real age.
