In Beijing in the early 1970s, busy with "making revolution", adults had no time to pay attention to children. In addition, the school was closed and there was nothing to do. Young people, with the boys in the military compound as the prominent representatives, made fun of themselves and squandered excessive hormones by making fun of themselves, fighting, making trouble, and patting women. Ma Xiaojun (Xia Yu) is such a young man. One of his hobbies is to sneak in and play while no one else uses the master key to open the lock. It is in this way that the photo of young girl Milan (Jing Jing) enters Ma Xiaojun's eyes before the person. Through Liu yiku (Geng LE), the "leader" in the courtyard, Ma Xiaojun meets Milan, whom he once glimpsed in the artillery Bureau, and begins to officially regard him as the lover of his dream. However, in Milan's eyes, Ma Xiaojun is just a baby, and the person she likes is mature, steady and handsome Liu yiku. Since then, Ma Xiaojun has ushered in a mixed adolescence.

In Beijing in the early 1970s, busy with "making revolution", adults had no time to pay attention to children. In addition, the school was closed and there was nothing to do. Young people, with the boys in the military compound as the prominent representatives, made fun of themselves and squandered excessive hormones by making fun of themselves, fighting, making trouble, and patting women. Ma Xiaojun (Xia Yu) is such a young man. One of his hobbies is to sneak in and play while no one else uses the master key to open the lock. It is in this way that the photo of young girl Milan (Jing Jing) enters Ma Xiaojun's eyes before the person. Through Liu yiku (Geng LE), the "leader" in the courtyard, Ma Xiaojun meets Milan, whom he once glimpsed in the artillery Bureau, and begins to officially regard him as the lover of his dream. However, in Milan's eyes, Ma Xiaojun is just a baby, and the person she likes is mature, steady and handsome Liu yiku. Since then, Ma Xiaojun has ushered in a mixed adolescence.