This article aims to illuminate forms of transformative instructional practices that encourage a sense of agency, responsibility, and motivation in student learning by intervening in their "self-affirmation." Self-affirmation is subjective work done to create and construct new meaning while preserving a sense of personal integrity, competence, social belonging, and purpose in coping with threatening events in educational settings. In this article, transformative instructional practices, such as enhancing children's self-affirmation, which are embodied in collaborative and purposeful activities at school, are conceptualized through the framework of cultural-historical activity theory. The data used in this article were obtained from ethnographic research on pedagogical practices in a municipal elementary school in Gifu City, Japan. Based on an analysis of some typical examples from the collected data, it was concluded that the transformative instructional practice in schools that necessarily accompanies the intervention in self-affirmation is realized through expansive learning by children. This expansive learning is learning in which children themselves independently collaborate and create a "society-oriented" system of learning activity that can promote and support the affirmation of a "self-oriented" system.