  Flavor mixings together with fermion mass spectra are studied in detail in
the $SU(6) \times SU(2)_R$ model, in which state-mixings beyond the minimal
supersymmetric standard model (MSSM) take place. Characteristic patterns of
fermion spectra are attributed to the hierarchical structure of effective
Yukawa interactions via the Froggatt-Nielsen mechanism and also to the
state-mixings beyond the MSSM. It is shown explicitly that the neutrino mass
matrix in the mass diagonal basis for charged leptons has no hierarchical
structure. This is due to the cancellation among the hierarchical factors by
the seesaw mechanism with the hierarchical Majorana mass matrix of $R$-handed
neutrinos. As a consequence, $V_{\rm MNS}$ exhibits large mixing. It is found
that observed values of the Maki-Nakagawa-Sakata matrix elements are reproduced
successfully.
