Extra-Syntactic Subject Positions in Japanese Discourse: A Minimal Four-Layer Model

Japanese discourse frequently omits overt subjects, yet interlocutors rarely experience communicative breakdown. This paper proposes a minimal four-layer model of subject representation that operates beyond the grammatical sentence. The model provides a structural explanation for topic–comment phenomena, zero-anaphora, and intersubjective stance-taking, while avoiding culture-specific assumptions. Additional parallels with historical authentication systems (e.g., wax seals) illustrate how information outside the explicit text contributes to interpretation. The model also predicts characteristic patterns of AI misreadings when surface cues are absent. This theory is derived entirely from established international research on pragmatics, cognitive linguistics, and intersubjectivity, ensuring compatibility with existing debates.