This paper presents closure within the first system of Kasei-Theory as a non-modal readability maintainability architecture. The paper does not propose a theory of completion, finality, total integration, universal stabilization, perfected continuity, terminal configurational fulfillment, completion-derived fulfillment, finality-derived termination, totality-derived integration, boundary-derived limit, or transcendental closure order. Instead, it fixes closure, constrained closure, configurational differentiation, local maintainability, unreadability, formal closure, non-completed closure, and non-totality as distributed structural positions within constrained local readability maintainability. Closure is not treated as completion, finality, fulfillment, totality, or perfected continuity, but as constrained local closure under which configurational differentiation remains locally maintainable without universal completion, finalized totality, terminal fulfillment, completed integration, or total configurational closure. Closure does not establish completion. Closure does not establish finality. Closure does not establish fulfillment. Closure does not establish terminal configurational fulfillment. Closure remains fixed only as constrained local closure within readability maintainability. This paper fixes only the local closure conditions under which configurational differentiation remains maintainable without transition into universal stabilization, completed continuity, completion-derived fulfillment, finality-derived termination, totality-derived integration, boundary-derived limit, or total configurational integration. No subject is presupposed. No finalized structure is established. No universal completion structure is secured. No total configurational closure is completed. This paper is part of Kasei-Theory.