Yu Xia, an ordinary girl, even a little shy. From elementary school to the first year of high school, she has been unknown. She seems to have a good relationship with all her classmates, but she doesn't seem to be that close. In her freshman year of high school, they met on the basketball court and he broke into her life. He is so cheerful and sunny, just like the sun in winter, giving people warmth. With his encouragement, she gradually changed, became more smiley, and took the initiative to communicate with her classmates. However, just when she changed for him, he wanted to leave her...