This chapter presents the theoretical foundation and conceptual architecture of Identity Restoration Theory (IRT), outlining its philosophical assumptions, core principles, and restorative constructs. It situates IRT within interdisciplinary scholarship on criminology, restorative justice, adult learning, and psychology, addressing limitations in traditional rehabilitation models that focus on behavioral modification without attending to identity, culture, and moral coherence. The chapter articulates the five core restorative constructs of IRT: cultural memory, place reconnection, narrative repair, communal belonging, and agency activation, and explains how their interaction supports sustainable personal transformation. Attention is given to the restorative cycle through which these constructs operate as an integrated process rather than isolated interventions. The chapter also defines the scope, boundary conditions, and practical implications of the theory for educational and correctional contexts. Formalizing IRT as a coherent theoretical framework, this chapter establishes its relevance for research, policy development, and culturally grounded rehabilitation practices aimed at reducing recidivism through identity reconstruction.