  We study type II supernova signatures of neutrino mass generation via
symmetry breaking at a scale in the range from keV to MeV. The scalar
responsible for symmetry breaking can be thermalized in the supernova core and
restore the symmetry. The neutrinos from scalar decays have about half the
average energy of thermal neutrinos and are Bose-Einstein distributed. We find
that, even without a detailed knowledge of the supernova parameters, a
discovery is well within reach at Super-Kamiokande.
