  We report CCD photometry and analysis of the first observed superoutburst of
the SU UMa-type dwarf nova KP Cassiopeiae during 2008 October. We observed a
distinct shortening of the superhump period at superhump cycle 15. Before that
point Psh was 0.08556(3) d and afterwards it evolved from 0.08517(2) d to
0.08544(3) d with a rate of period change dPsh/dt = 3.2(2) * 10-5. We measured
the likely orbital period as 0.0814(4) d placing KP Cas just below the period
gap. The superhump period excess is 0.048(5) and, empirically, the mass ratio q
is 0.20(2). The superoutburst lasted between 8 and 12 days, peaked close to
magnitude 13 with an amplitude above quiescence of 5 magnitudes, and faded for
4 days at a rate of 0.14 mag/d. Close monitoring following the end of the
superoutburst detected a single normal outburst 60 days later which reached
magnitude 14.7 and lasted less than 3 days.
