Zhao Rurui and Zhao Ruxin are a pair of sisters. Older sister Rurui has been a top student since she was a child was on the way to become a doctor. Compared to her the high school student Ruxin is deemed very mediocre, she is not valued by her parents and teachers, and is jealous of her sister Rurui. On the eve of Ruxin's college entrance examination, Rurui dies in a car accident, which causes a huge blow to the family. Ruxin finds a second mobile phone in Rurui's things and puzzled by her sister's death travels to the big city where her sister lived alone.
