  The flavor moonshine hypothesis is formulated to suppose that all particle
masses (leptons, quarks, Higgs and gauge particles -- more precisely, their
mass ratios) are expressed as coefficients in the Fourier expansion of some
modular forms just as, in mathematics, dimensions of representations of a
certain group are expressed as coefficients in the Fourier expansion of some
modular forms. The mysterious hierarchical structure of the quark and lepton
masses is thus attributed to that of the Fourier coefficient matrices of
certain modular forms. Our intention here is not to prove this hypothesis
starting from some physical assumptions but rather to demonstrate that this
hypothesis is experimentally verified and, assuming that the string theory
correctly describes the natural law, to calculate the geometry (K\"{a}hler
potential and the metric) of the moduli space of the Calabi-Yau manifold, thus
providing a way to calculate the metric of Calabi-Yau manifold itself directly
from the experimental data.
