This is a story about youth. Xu Nuo, a first-year high school girl with dual personality, Gu Chengyuan, a young man with a gentle appearance but never admit defeat at heart, Xu Nuo's best friend, the beautiful girl Xia Xiqiao, and Lin Qiumo, a sophomore senior in high school. In their extremely brilliant years, they hugged each other to keep each other warm, and they freely expressed their happiness in their youth, like brave and tenacious sunflowers, with warmth on one side and sadness on the other. When the outcome of everything will be revealed, what kind of future will they choose? Faced with the unknown conspiracy, will they face it bravely or flee in all directions? Thank you, thank you for allowing me a joy in these youthful years, even if it is an empty joy in the end...