  We study predictions of orbifold family unification models with $SU(9)$ gauge
group on a six-dimensional space-time including the orbifold $T^2/Z_2$, and
obtain relations among sfermion masses in the supersymmetric extension of
models. The models have an excellent feature that just three families of the
standard model fermions exist in a pair of Weyl fermions in the $[9, 3]$
representation as four-dimensional zero modes, without accompanying any mirror
particles.
