  We present a $U(4)_R \times U(4)_L$ chirally symmetric model, which in
addition to scalar and pseudoscalar mesons also includes vector and
axial-vector mesons. A part from the three new parameters pertaining to the
charm degree of freedom, the parameters of the model are fixed from the $N_f=3$
flavor sector. We calculate open charmed meson masses and the weak decay
constants of nonstrange open charm $D$ and strange open charm $D_S$. We also
evaluate the (OZI-dominant) strong decays of open charmed mesons. The results
are turn out to be in quantitative agreement with experimental data.
