重新整理好心情的由加里打算把对方留在这里的最后一样物品——家中的钥匙还回去，“可是当时得到钥匙时的心情，即使到现在都能记得，就像是拿到了打开通往世界之门的钥匙一样……”3年前的甜蜜的圣诞节在脑海中清晰起来。
麻美（安藤樱 饰）是一名33岁的平凡公务员，有一个妹妹遥（志田未来 饰），姐妹之间的关系十分的要好。麻美还有两个好朋友夏希（夏帆 饰）和美穗（木南晴夏 饰），三人在闲暇时常常在一起玩。
Elya, 20, is a student and a future ecologist. One day, Matvey, the head of a construction company, came to her university to discuss the development plan for an old forest park. Elya did not hesitate to crush his project. Matvey is very interested in girls' confidence, And used his usual influence method - he just tried to ; purchase She, but Elya doesn't need a sponsor. Then, Matvey was surprised by her indestructibility and placed a bet on Elya: romantic seven days according to his rules. If the girl still decides to leave after that, he will refuse to build a skyscraper in the forest park. When Matvey really paused design work, she agreed. Elya thinks she's a bit like the movie 'Beautiful Woman' The female protagonist in, but it turns out that Matvey is not the person she imagined.
