Unfolded hypermultiplet in harmonic superspace

We construct an unfolded system that describes an on-shell free massless hypermultiplet and show that the standard harmonic superspace formulation of this model naturally arises from the "vielbeinization" of unfolded 1-forms associated to R-symmetry. Moreover, using this system as an example, we demonstrate the phenomenon of background universality of the unfolded dynamics approach: we systematically deduce formulations in harmonic, N=2, and N=1 superspaces, as well as the component formulation in Minkowski space, directly from this unfolded system. We also comment on a putative off-shell extension of the on-shell system we constructed, and show how the harmonic contribution is reflected in the universal unfolded fiber.