  We present spectroscopy of stars in the immediate vicinity of the dwarf nova
(DN) KZ Gem to confirm its identification, which had been ambiguous in the
literature. Analysis of 73 radial velocities spanning from 2014 to 2019
provides a high-precision orbital period of 0.2224628(2)\,d ($\sim5.34$\,hr)
and shows KZ\,Gem to be a double-lined DN. Time series photometry taken from
2016 to 2018 shows a variable double-hump modulation with a full amplitude of
$\sim0.3$\,mag, along with five Gaussian-like transient events lasting
$\sim30$\,min or more. Using the light curve code XRBinary and nonlinear
fitting code NMfit, we obtain an optimized binary model of the dwarf nova (DN)
KZ Gem, from time series photometry, consisting of a Roche-lobe-filling K type
dwarf with a mass transfer rate of $2.7\,-\,7.9\times10^{-10}\,{\rm
M}_{\odot}\,{\rm yr}^{-1}$ to a large, cool and thick disk surrounding a white
dwarf, in an orbit with an inclination of $51^{\circ}.6(\pm1^{\circ}.4)$. Two
hotspots on the disk are demonstrated to cause the observed variations in the
ellipsoidal modulations from the secondary star. This physical model is
compatible with the Gaia distance of KZ\,Gem.
