  We study the binding energy differences of the valence proton and neutron of
the mirror nuclei, $^{15}$O - $^{15}$N, $^{17}$F - $^{17}$O, $^{39}$Ca -
$^{39}$K and $^{41}$Sc - $^{41}$Ca, using the quark-meson coupling model. The
calculation involves nuclear structure and shell effects explicitly. It is
shown that binding energy differences of a few hundred keV arise from the
strong interaction, even after subtracting all electromagnetic corrections. The
origin of these differences may be ascribed to the charge symmetry breaking
effects set in the strong interaction through the u and d current quark mass
difference. In this report, we first review the quark-meson coupling model. In
particular, we discuss about the nucleon mass in nuclear medium. Then, we
present details of the charge symmetry breaking in finite nuclei, especially
the Okamoto-Nolen-Schiffer anomaly.
