  Let V be a simple C_2-cofinite VOA of CFT-type and we assume that there is a
simple module U such that \Hom_V(U\boxtimes V',V)\not=0 where V' is a
restricted dual of V. As the author has shown, an S-transformation S(\Psi_V) of
a trace function \Psi_V on V corresponding \begin{pmatrix}0&-1\cr
1&0\end{pmatrix} may contain pseudo-trace functions. Our assumption in this
paper is that no pseudo-trace functions appear in S(\Psi_V). Under these
assumptions, we prove that every V-module W is semirigid and \Psi_W appears in
S(\Psi_V). As a corollary of our main theorem, a fixed point subVOA of a
rational VOA of CFT-type by an automorphism of finite order becomes rational if
fixed point subVOA is C_2-cofinite.
