The reorientational relaxation of nonlinear molecules in liquids is treated using the site-site generalized Langevin/mode-coupling theory. We found an inconsistency between the rank-1 reorientational correlation functions of different vectors on a molecule when the molecule is nearly planar. We show that it is because the coupling between the torque and the acceleration of different rotational modes is missing in the theory. A modification of the theory is proposed to incorporate this coupling, and the inconsistency between the reorientational correlation functions is remedied by the modification. We also apply the modified theory to the reorientational motion of water. The rotational part of the memory function becomes greater compared with the conventional theory, and it approaches to that from the molecular dynamics simulation. The charge-current spectrum of water is also shown to be improved by the modification.