  In this work we extend Onofri and Perelomov's coherent states methods to the
recently introduced $OSp(1/2)$ coherent states. These latter are shown to be
parametrized by points of a supersymplectic supermanifold, namely the
homogeneous superspace $OSp(1/2)/U(1)$, which is clearly identified with a
supercoadjoint orbit of $OSp(1/2)$ by exhibiting the corresponding equivariant
supermoment map. Moreover, this supermanifold is shown to be a nontrivial
example of Rothstein's supersymplectic supermanifolds. More precisely, we show
that its supersymplectic structure is completely determined in terms of
$SU(1,1)$-invariant (but unrelated) K\"ahler $2$-form and K\"ahler metric on
the unit disc. This result allows us to define the notions of a superK\"ahler
supermanifold and a superK\"ahler superpotential, the geometric structure of
the former being encoded into the latter.
