  We report that HAT-P-7 has a common proper motion stellar companion. The
companion is located at $\sim3.9$ arcsec to the east and estimated as an M5.5V
dwarf based on its colors. We also confirm the presence of the third companion,
which was first reported by Winn et al. (2009), based on long-term radial
velocity measurements. We revisit the migration mechanism of HAT-P-7b given the
presence of those companions, and propose sequential Kozai migration as a
likely scenario in this system. This scenario may explain the reason for an
outlier in the discussion of the spin-orbit alignment timescale for HAT-P-7b by
Albrecht et al. (2012).
