17-year-old Xiaokui (He Meiqi) grew up in a seaside county town. She excels in her studies, loves to follow teen idols, and everyone in the neighborhood knows she has a best friend named Qiangwei (Yan Yunjing), a math genius who transferred back from the city. No romance, no cell phone, only geography magazines and a big TV at seventeen. An "aurora" secretly descends upon this county town. Faced with day-to-day life, the forever familiar faces in the neighborhood, this endless sea and a life that can be seen through in a glance—can the answers be found in the math problems of five years of college entrance exams and three years of practice tests? The girl sits on an old fishing boat, fantasizing that if they could fix this boat, perhaps they could leave this place.