  In this short review, we see some typical models in which light neutrino
masses are generated at the loop level. These models involve new Higgs bosons
whose Yukawa interactions with leptons are constrained by the neutrino
oscillation data. Predictions about flavor structures of $\ell \to
\overline{\ell}_1 \ell_2 \ell_3$ and leptonic decays of new Higgs bosons via
the constrained Yukawa interactions are briefly summarized in order to utilize
such Higgs as a probe of $\nu$ physics.

High Energy Physics - Phenomenology