  This paper deals with a limiting case motivated by contact geometry. The
limiting case of a tensorial characterization of contact hypersurfaces in
Kahler manifolds leads to Hopf hypersurfaces whose maximal complex subbundle of
the tangent bundle is integrable. It is known that in non-flat complex space
forms and in complex quadrics such real hypersurfaces do not exist, but the
existence problem in other irreducible Kahler manifolds is open. In this paper
we construct explicitly a one-parameter family of homogeneous Hopf
hypersurfaces, whose maximal complex subbundle of the tangent bundle is
integrable, in a Hermitian symmetric space of non-compact type and rank two.
These are the first known examples of such real hypersurfaces in irreducible
Kahler manifolds.
