This study attempted to examine the changes and growth of elementary school students in a dynamic social group, a class, experiencing self-governing class rules enactment and practical activities. To this end, participatory observation was conducted on one class(11 males and 15 females) in the third grade of elementary school for 6 class meetings and rule practice activities for 11 weeks. As a result of the study, participants in the study recognized the concept of class rules as sanctions in the process of meeting to enact class rules, expressed self-government skills inherent in the study participants, and showed distrust of themselves and others. In the process of implementing class rules, class rules were recognized as a criterion for judging overall school life, and they grew in terms of personality and sociality, but they also showed exchanges of abuse of authority and solicitations related to class rules. The process of enacting and implementing these class rules fostered students' leading life skills and was an opportunity to see what gaps exist in school education that realizes future competency-building education. And based on this, implications for improving school and class autonomy activities were presented.