  For raising the radiative Higgs mass without a serious fine-tuning in the
Higgs sector, we introduce vector-like lepton doublets and neutral singlets
{L,L^c; N,N^c}, and consider their order one Yukawa coupling to the Higgs, W
\supset y_NLh_uN^c. The 125 GeV Higgs mass can be naturally explained with the
stop mass squared of ~(500 GeV)^2 and even without the "A-term" contributions.
It is possible because of the quartic power of y_N in the radiative Higgs mass
correction, and much less stringent mass bounds on extra leptonic matter. In
order to avoid blowup of y_N at higher energy scales, a non-Abelian gauge
extension of the MSSM is attempted, under which {L,L^c; N,N^c} are charged,
while all the ordinary MSSM superfields remain neutral. We discuss the gauge
coupling unification. This mechanism can be applied also for enhancing h^0
\rightarrow \gamma\gamma with W \supset y_EL^ch_uE, if the charged lepton
singlets {E,E^c} are also introduced.
