在这部晴天娃娃剧情/爱情片中,处于青春期的少年人总会有因爱而生的或忧伤或甜蜜的小情绪，克磊（范植伟）与歆荷（李康宜）也不例外。
两人是台湾某所高中普通高二生，分别在于，一个沉默孤傲，数学成绩一极棒，在学校属“王子”，另一个则整天幻想上帝派她一个同她有一样想法的男朋友，数学成绩超级烂，属“灰姑娘”。当两人由校长牵线（克磊帮助歆荷补习数学）而结识时，相处初期没少矛盾和别扭。但时间慢慢向前，一种说不清讲不明的时开心时沮丧的感觉从彼此心中生出，而雨季来临时，无法见面自不会再争吵的两人，都分明感受到了时间的停滞不前。心事所趋，歆荷做了个晴天娃娃乞求天晴，故事开始朝之前两人不曾想过的方向上走。
Hsin-He, a high school sophomore who can get along just fine on her own, lives with her father. At school, the days pass slowly by, as if in perpetual anticipation. One day, just when her mind is wandering off yet again in the middle of math class, the teacher assigns her to be the student teacher. Hsin-He, a self-acknowledged math dunce, is left frustrated and annoyed. Knowing this, Teacher Tan orders that Fang Ke-Lei, a male classmate who is a math whiz and student teacher of a different class, tutors Hsin-He in math and that Hsin-He assists Ke-Lei with administrative tasks. Ordered to work together like this, the two find themselves not getting along; Ke-Lei is reticent and arrogant, and Hsin-He writes him off as an egomaniac. Hsin-He thinks that he won't be back to tutor her again, and she can go back to her happy, solitary life. But one day, Ke-Lei shows up unexpectedly on the school bus. Making a sincere effort, he says that he has decided to use this time to tutor her. But he explains that on rainy days, he will still take his family car. It's the rainy season, and Hsin-he is sitting by herself on the school bus. Whether it's at school, at home, or on the street, she keeps feeling this inexplicable discomfort, perhaps due to the oppressive, wet weather. So she makes a miniature "sunny doll" to ask for sunny weather.
记忆中的电影。时光 散场。青春。余韵回肠。青春记忆--晴天娃娃。台湾的海风。其实这才是真实的爱情，与疯狂无关，只有试探与怀疑。那个干净的短发少年。关于《晴天娃娃》。你与我都是数学白痴。
