This paper presents the self-narration of an elementary school teacher to describe stories regarding various challenges at school. Activity theory is adopted as the reference framework of story plots and dialogues so as to analyze their sociocultural context and to present the expansive learning process of the teacher. The purpose of this paper is to examine the systems and operations related to teaching activities based on the framework of activity theory. Specifically, the teaching stories are explored to observe scenario changes engendered by related disturbances, and the effects of these changes from the perspective of conflict are analyzed, thus enabling a close examination of the teacher’s conflicts while experiencing these disturbances and discussing the teacher’s reinterpretation of teaching activities. The conclusions of the study are as follows. (1) Teaching is a group activity and should be examined through the overall context. While actualizing their teaching ideas, teacher undergo various mediating processes, including the creation and application of teaching tools and interaction with their peers to assign tasks and define related rules. An activity system is operated under a scenario context, and mediating processes are affected by cultural and historical factors so as to demonstrate the values of the social environment. (2) Facing challenges with a positive attitude helps facilitate the development of teachers’ teaching professionalism. When teachers face conflicts, they experience frustration and tension, but through the process of coping with tension and formulating problem-solving strategies, they can gain a greater understanding of related problems and the environment, helping them develop their teaching professionalism. (3) When faced with disturbances and conflicts, teachers should conduct introspection through self-understanding and formulate strategies for subsequent teaching activities.