日本女生橘子（加藤侑纪饰）到台湾来学习中文，她找了一份兼职，边工作边学习，她给自己定下的学习期限为不超过四个月，这期间，在一个偶然的机会里，她结识了台客摇滚乐团 “猴子电童”的主唱吴奇峰（周渝民饰）并互生好感。

橘子知道这段恋情可能没有未来，而吴奇峰一直嫌弃谈恋爱过于麻烦，二人抱着各自的心思开始了这段恋情，不过，他们事先约定好并签下了合同，给恋爱订下的期限为90天，等到了截止日那天，他们就快乐分手，这样就可以不用考虑未来的发展，也不用顾虑分手时的心情。

起初，这段为期90天的恋爱让二人都非常开心，但随着时间的推移和双方的深入了解，恋爱中游戏的成分越来越少了，彼此眼中多了深情，多了真心，都想为对方付出些什么，眼看就要到了约定的期限，二人陷入了痛苦之中，橘子马上要回日本了，吴奇峰必须要做点什么来挽回与橘子的恋情。

A Japanese girl Tangerine (played by Yuki Kato) came to Taiwan to study Chinese. She found a part-time job and studied while working. The duration of her study is no more than four months. During this period, by chance, she met Wu Qifeng (played by Zhou Yumin), the lead singer of the Taiwanese rock band "Monkey Electronic Boys", and they had a good relationship

Orange knows that this relationship may have no future, but Wu Qifeng has always disliked that dating is too troublesome, and the two started with their own ideas. However, they made an agreement in advance and signed the contract, and the time limit set for the relationship is 90 days. When the deadline is reached, they will happily break up, so that they don't have to think about future development, and don't have to worry about it. The mood when breaking up.

At first, this 90-day relationship made both of them very happy, but with the passage of time and the in-depth understanding of both sides , the elements of games in love are becoming less and less, each other has more affection and sincerity in their eyes, and they both want to give something for each other. Seeing that the agreed deadline is coming, the two are in pain, and the orange is about to return. Japan is gone, Wu Qifeng must do something to save his relationship with Juzi.