Under the strict education of her father, Pei Yuyan was a good student at school and practiced piano at home. Following her parents' wishes, she lived quietly like a canary in a cage. What made her smile was the occasional pop songs that she was forbidden to touch. She thought everything would go according to her father's plan. She graduated from high school and went abroad, studied music, and played classical piano... until she met Yu Hao, the gangster who fought on the street, the student who rushed into the classroom to thank her, and the boy who stopped the bus and handed over a love letter! Yu Hao, whose parents died, was taking care of the policeman Uncle Hui and was walking towards the day of high school graduation. He and Danzi and Aqi, who grew up together, were always together, whether good or bad. They walked with the wind in school and fought fiercely outside of school. Yu Hao remembered every move of Pei Yuyan who took the first step towards him who was injured that day. Although the two worlds were very different, he couldn't help but grasp this love that moved his heart. Taking Yan Zi at full speed and seeing her smiling happily, Yu Hao decided to do everything he could to protect this girl who had entered his youth...