  We investigate the electronic density redistribution of rotated bilayer
graphene under a perpendicular electric field, showing that the layers are
actually coupled even for large angles. This layer-layer coupling is evidenced
by the charge transfer on these structures as a function of the external
voltage. We find an inhomogeneous excess charge distribution that is related to
the moir\'e patterns for small angles, but that persists for larger angles
where the carriers' velocity is equal to that of single layer graphene. Our
results show that rotated bilayer systems are coupled for all rotation angles.
