  We study the behaviour of five-dimensional fermions localized on branes,
which we describe by domain walls, when two parallel branes collide in a
five-dimensional Minkowski background spacetime. We find that most fermions are
localized on both branes as a whole even after collision. However, how much
fermions are localized on which brane depends sensitively on the incident
velocity and the coupling constants unless the fermions exist on both branes.
