  We discuss on the search for the right-handed weak interaction effects in the
SU(2)$_L \times$SU(2)$_R$ model with lepton doublets $(\nu_\ell, \ell^-)_L$ and
$(N_\ell, \ell^-)_R$ ($\ell = e, \mu, \tau)$. We will point out that only the
chance of the observation of the right-handed weak interaction effect will be
in the rare decay $K^+ \rightarrow \pi^- \mu^+ \mu^+$.
