  Masses of open- and hidden-charm tetra-quark scalar mesons are studied in a
new approach. As the result, newly estimated masses of hidden-charm sector are
significantly lower than our earier ones by a naive quark counting. In
particular, our new result on the non-strange iso-triplet scalar mesons should
be compared with the experiment that an indication of tiny eta pi peak around
3.2 GeV has been observed, while no signal in the eta_c pi channel.
