  We consider chaotic inflation models with a pseudo-scalar field containing
the general couplings to the four-form flux. The four-form mixing with the
pseudo-scalar field induces a quadratic potential for inflaton while the
coexisting four-form mixing with graviton generates a non-minimal gravity
coupling for inflaton. The shift symmetry is respected by the derived inflaton
couplings and it is broken spontaneously only by the fixed four-form flux. We
discuss the success of inflationary predictions and robustness against higher
order terms. Finally, the built-in reheating mechanism is also addressed.
