  The decay $b\to s\nu\bar\nu$ has been a neglected sibling of $b\to
s\ell^+\ell^-$ because neutrinos pass undetected and hence the process offers
less number of observables. We show how the decay $b\to s~+$~invisible(s) can
shed light, even with a limited number of observables, on possible new physics
beyond the Standard Model and also show, quantitatively, the reach of future
$B$ factories like SuperBelle to uncover such new physics. Depending on the
operator structure of new physics, different channels may act as the best
possible probe. We show, using the Optimal Observable technique, how almost the
entire parameter space allowed till now can successfully be probed at a high
luminosity $B$ factory.
