  Experiments on neutrino oscillations have uncovered several small parameters,
$\theta_{13}$ being a prominent one. Others are the solar mass splitting {\em
vis-\`{a}-vis} the atmospheric one and the deviation of $\theta_{23}$ from
maximal mixing. In this talk we elaborate on a neutrino mass model based on the
see-saw mechanism in which the mixing angles to start with are either vanishing
($\theta_{13}$ and $\theta_{12}$) or $\pi/4$ ($\theta_{23}$). The atmospheric
mass splitting is taken as a part of this initial structure but the solar
splitting is absent. A perturbative contribution, originating from a Type-I
see-saw, results in non-zero values of $\theta_{13}$, $\theta_{12}$, $\Delta
m^2_{solar}$, and shifts $\theta_{23}$ slightly from $\pi/4$, interrelating
them all. The model incorporates CP-violation, the phase $\delta$ being close
to 3$\pi$/2 for (a) quasi-degeneracy or (b) inverted mass ordering. It will be
put to test as the neutrino parameters get better determined.
