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.,Because at that time, only one of the three was single, and they had sworn an oath when they made a pact of brotherhood: "A friend's wife is off-limits...",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...。