We apply the empirical quark mass matrices to the lepton sector and study the solar neutrino problem and the atmospheric vμ deficit problem simultaneously. We show that their consistent explanation is possible on the basis of these matrices. The lepton sector mass matrices need the phase structure which is different from the ones of the quark sector. However, even if the phase structure of the mass matrices is identical in both sectors, an interesting suppression mechanism of sin 2 2θ12 which is related to the solar neutrino problem can be induced from the right-handed neutrino Majorana mass matrix. We discuss such a possibility through the concrete examples.