Quark and Lepton Mass Matrices with a Cyclic Permutation Invariant Form
  As an attempt to give an unified description of quark and lepton mass matrices M_f, the following mass matrix form is proposed: the form of the mass matrices are invariant under a cyclic permutation (f_1 \to f_2, f_2 \to f_3, f_3 \to f_1) among the fermions f_i. The model naturally leads to the maximal mixing between \nu_\mu and \nu_\tau, and with an additional ansatz, it leads to the well-satisfied relations |V_{us}| \simeq \sqrt{m_d/m_s} and |V_{cb}| \simeq \sqrt{m_d/m_b}. 
Yoshio Koide