They are said to be sworn brothers, no matter what they do, they always do it together. They skip class together, fight together, eat together, play games together, and share a dormitory room. They share everything, except perhaps a girlfriend.,There's also Liu Xing, who once went to find the hooligan who stabbed Zhang Yi and Guan Hao for them. He fought with him until they were both covered in blood and bruises, even ending up in jail...,Zhang Yi fell silent for a moment: "Let's not dwell on the past."。