Abstract: This paper proposes an alternative analysis of the Japanese so-called copula =da and its non-contracted form =de aru. While =da has traditionally been treated as a copula equivalent to English be, we argue instead that the essence of the Japanese pseudo-copula can be reduced to the question of how Japanese employs its most basic linguistic resources — namely, the locative postposition =ni, the conjunctive suffix -te and the existential verb ar- — which together functionally underlie =da — to denote relations between two entities. The function of =da and its non-contracted form =de aru is to indicate that something exists (ar-) and that, conjunctively (-te), this existence is specified as located in a conceptual domain (=ni). Under this conception, A=wa B=de aru 'A is B' is semantically analysed as both existence-asserting and existence-domain-specifying. Syntactically, it consists of the one-argument obligatory construction [A=wa aru] 'A exists' and the adjunct [B=de] — underlyingly [B=ni-te] — 'with (A's existence) located in the conceptual domain of B' or, more practically, 'and it is as B'. Schematically, this construction can be represented as the conjunctive proposition EXIST(A) ⋀ IN(rEXIST(A), B) — whose default negation pattern is not total but partial, namely E(A) ⋀ ¬IN(rE(A), B), realised as A=wa B=de=wa nai. Although B=de is syntactically adjunctive, it cannot be omitted because it is information-structurally indispensable: it marks the informational focus, whereas the syntactically obligatory A=wa aru provides the presuppositional background. This reanalysis appears to make possible a unified account of the structure, semantics and diachronic development of Japanese so-called copular constructions.