  We argue that there may arise a relatively flat inflaton potential over
super-Planckian field values with an approximate shift symmetry, if the
coefficients of the kinetic terms for many singlet scalars are subject to a
certain random distribution. The inflaton potential generically contains
various shift-symmetry breaking terms, leading to a possibly large deviation of
the predicted values of the spectral index and tensor-to-scalar ratio from
those of the simple quadratic chaotic inflation. We revisit a polynomial
chaotic inflation in supergravity as such.
