This paper proposes, ‘constitutional unification’ as a planned way of reconciling the two Koreas as historical and structural enemies. From a normative perspective, this paper aims to demonstrate the extraordinary political act of constitution-building as a potentially both legitimate and necessary means for achieving reconciliation between political enemies. To do so, this paper explains why constitution-building is a desirable means of democratically transforming adversaries into political actors that together take up a task of a new beginning. It thereafter defines the three distinct but intertwined dimensions of constitution-building in political reconciliation; political, ethical, and legal. In its political sense, constitution-building refers to the founding act by which a space for politics is established. In the legal sense, constitution-building refers to the fundamental law of the polity laid down through the founding act. In its third ethical sense, constitution- building refers to the emergence of a “we” as an identifiable entity in the act of foundation. Together, these three dimensions clearly portray political reconciliation as a total reconfiguration of a regime or community in the interaction of politics, law, and ethics. Finally, appropriating John Rawls’s neutrality of aim, it argues that the people of the two Koreas will endorse reconciliation through constitution-building because the harm suffered by both sides as a result of their enemy relationship far overrides whatever they might lose in the process.