  The common lore in the literature of neutrino mass generation is that the
canonical see-saw mechanism beautifully offers an explanation for the tiny
neutrino mass but at the cost of introducing right-handed neutrinos at a scale
that is out of range for the current experiments. The inverse see-saw mechanism
is an interesting alternative to the canonical one once it leads to tiny
neutrino masses with the advantage of being testable at TeV scale. However,
this last mechanism suffers from an issue of naturalness concerning the scale
responsible for such small masses, namely, the parameter $\mu$ that is related
to lepton number violation and is supposed to be at the keV scale, much lower
than the electroweak one. However, no theoretical framework was built that
offers an explanation for obtaining this specific scale. In this work we
propose a variation of the inverse see-saw mechanism by assuming a minimal
scalar and fermionic set of singlet fields, along with a $Z_5\otimes Z_2$
symmetry, that allows a dynamical explanation for the smallness of $\mu$,
recovering the neat canonical see-saw formula and with right-handed (RH)
neutrinos free to be at the electroweak scale, thus testable at LHC and current
neutrino experiments.
