  We study flavor violation in a supersymmetric SU(5) grand unification
scenario in a model-independent way employing mass insertions. We examine how
the quark and the lepton sector observables restrict sfermion mixings. With a
low soft scalar mass, a lepton flavor violating process provides a stringent
constraint on the flavor structure of right-handed down-type squarks. In
particular, mu -> e gamma turns out to be highly susceptible to the 1-3 and 2-3
mixings thereof, due to the radiative correction from the top Yukawa coupling
to the scalar mass terms of 10. With a higher scalar mass around the optimal
value, in contrast, the quark sector inputs such as B-meson mixings and hadron
electric dipole moment, essentially determine the room for sfermion mixing. We
also discuss the recent deviation observed in B_s mixing phase, projected
sensitivity of forthcoming experiments, and ways to maintain the power of
leptonic restrictions even after incorporating a solution to fix the incorrect
quark-lepton mass relations.
