  We present the multi-color, five-year light curves and the first radial
velocities of the near-contact binary system KR Cyg. We derived the masses of
the components as 2.88$\pm$0.20 M$_{\odot}$ and 1.26$\pm$0.07 M$_{\odot}$ and
the radii as 2.59$\pm$0.06 R$_{\odot}$ and 1.80$\pm$0.04 R$_{\odot}$. Analyses
of the UBVR light curves and the radial velocities indicate that none of the
components exactly fill their corresponding Roche lobes. We have calculated the
distance to the system of KR Cyg as {411$\pm$12} pc using the observed apparent
UBV magnitudes and the bolometric corrections for the component stars. We also
searched for the empirical determination of albedo and effective temperature of
the cooler, less massive star of KR Cyg, and of two similar near contact
binaries AK CMi, and DO Cas. The residuals between the observed and computed
fluxes are attributed to the effect of mutual illumination which heats the
surface layers of the illuminated star and does vary not only its bolometric
albedo but also its limb-darkening coefficient and gravity-brightening
exponent. The analysis of the light curves shows that the effective albedos are
generally smaller than that expected from an envelope of convective star, being
mostly departed from the theoretical value at the B passband. As the reflected
light diminishes the effective temperature and, therefore, the luminosity of
the irradiated star increase. The observed bluer U-B colors during primary
minimum are attributed to the effects of mutual irradiation and multiple
scattering processes which may alter several characteristics of these systems.
