  We study how the multi-channel Kondo effect is dynamically induced to affect
the photoemission and the inverse photoemission spectrum when an electron is
emitted from (or added to) the completely screened Kondo impurity with spin
$S>1/2$. The spectrum thereby shows a power-law edge singularity characteristic
of the multi-channel Kondo model. We discuss this anomalous behavior by using
the exact solution of the multi-channel Kondo model and boundary conformal
field theory. The idea is further applied to the photoemission for quantum spin
systems, in which the edge singularity is controlled by the dynamically induced
overscreening effect with a mobile Kondo impurity.
