In the late 1990s, there was a mining town in the south shrouded in the afterglow of prosperity. This town is a paradise. The doors and windows of every house in the town are basically sky blue. That kind of blue is very bold, as if it expresses the bright beauty of the young people who have traveled there from all over the world; that kind of blue is very simple, just like the sincere goodwill of the town. However, one day, this small world changed. All the people in the mine had no choice but to go their separate ways, and the town was forgotten in the corner of history. Only the children who have experienced its warm days and people who still have innocence in their hearts are still looking up to it and paying tribute to it.