At the beginning of the story, Qifeng, an extremely ordinary girl from Jiangnan, stood in the square of Su City Bar Street and looked inside from a distance. Qifeng has been in Sioux City for three years, but she is still quite unfamiliar with the bustling bar streets. This was the first time that she came with her classmate Zhang Di. It seems to be an established rule that the bar only starts to get lively at night, especially late at night. It seems that everyone who comes here is letting out their pent-up resentment all day long, shaking their heads to the heavy metal sound played by the DJ, and no one cares whether he really keeps up with the beat.