The main purpose of this paper is to provide a novel account for Wh-Concord in Okinawan based on the Copy Theory of Movement and Distributed Morphology. We propose that Wh-Concord interrogatives and Japanese-type wh-interrogatives have exactly the same derivation in the syntactic component: the Q-particle -ga, base-generated as adjoined to a wh-phrase, undergoes movement to the clause-final position. The two types of interrogatives are distinguished in the post-syntactic component: only in Wh-Concord, the -r morpheme on C0 triggers Morphological Merger, which makes it possible to Spell-Out lower copy of -ga. It is shown that the proposed analysis correctly predicts three descriptive generalizations on the distribution of -ga in (i) syntactic islands, (ii) subordinate clauses, and (iii) (embedded) multiple wh-interrogatives.