A second grade pupil Maomao, living in the border area between China and North Korea, found 34 certificates with a span of 16 years, some of which were written in Chinese, and some were Korean. All of these certificates belongs to a person called Yingbao Cui. Thus, Maomao came up with the idea of finding this stranger. In the process of searching, he gradually realized the vast, silence and loneliness of the world…