The main purpose of this paper was to identify how a school violence culture is developed and
reproduced. The study investigated the structure of violence and power beneath the nonun-aedul(literally
playing kids)’s peer culture in middle school transition period. In order to analyze the peer culture, we
conducted ethnographic case study for 2nd year middle school students who is a member of nounun-aedul
group. First, this paper demonstrates that peer group of nonun-aedul is established based on a school
violence culture. Second, frequent meeting among friends in elementary school is transmuted into
nonun-aedul's peer culture as transition to middle school occurs. In addition, although the level of the
violence depends on the degree of power, a violence in peer culture is used as a way of maintaining and
reproducing the power.