  Flavor symmetry has been widely studied for figuring out the masses and
mixing angles of standard-model fermions. In this paper we present a framework
for handling flavor symmetry breaking where the symmetry breaking is triggered
by boundary conditions of scalar fields in extra-dimensional space. The
alignment of scalar expectation values is achieved without referring to any
details of scalar potential and its minimization procedure. As applications to
non-abelian discrete flavor symmetries, illustrative lepton mass models are
constructed where the S3 and A4 flavor symmetries are broken down to the
directions leading to the tri-bimaximal form of lepton mixing and realistic
mass patterns.
