  Optical and near-infrared observations are compiled for the three gamma-ray
binaries hosting Be stars: PSR B1259-63, LSI+61 303, and HESS J0632+057. The
emissions from the Be disk are considered to vary according to the changes in
its structure, some of which are caused by interactions with the compact object
(e.g., tidal forces). Due to the high eccentricity and large orbit of these
systems, the interactions -- and, hence the resultant observables -- depend on
the orbital phase. To explore such variations, multi-band photometry and linear
polarization were monitored for the three considered systems, using two 1.5
m-class telescopes: IRSF at the South African Astronomical Observatory and
Kanata at the Higashi-Hiroshima Observatory.
