Neutrino Mass Texture with Large Mixing

We propose a very simple texture for the right-handed Majorana mass matrix to give a large $\nu_\mu-\nu_\tau$ mixing angle and hierarchical left-handed neutrino mass pattern. Consistently with the Dirac mass texture of the quark sector realizing the CKM mixing, this naturally explains the recent experimental results on both atmospheric neutrino oscillation made by the Superkamiokande collaboration and the solar neutrino problem.