  The search for multi-quark states beyond the constituent quark model (CQM)
has resulted in the discovery of many new exotic states, starting with the
observation of the X(3872), discovered by Belle in 2003. Also in the sector of
charm-strange physics the CQM does not seem to describe properly all spectrum,
despite of theoretical expectations. These new forms of quark bounds clearly
show that mesons and baryons are not the only possibilities to be considered.
We shortly report in this paper selected recent results on searching for such
states at Belle, with the perspectives in the hadron physics program at the
Belle II experiment.
