  We present our photometric studies of the newly discovered optical transient,
OT J012059.6+325545, which underwent a large outburst between 2010 November and
2011 January. The amplitude of the outburst was about 8 mag. We performed
simultaneous multi-color photometry by using g', Rc, and i'-band filters from
the early stage of the outburst. The time resolved photometry during the early
stage revealed periodic variations with double-peaked profiles, which are
referred to as early superhumps, with amplitudes of about 0.08 mag. After the
rapid fading from the main outburst, we found rebrightening phenomena, which
occurred at least nine times. The large amplitude of the outburst, early
superhumps, and rebrightening phenomena are typical features of WZ Sge-type
dwarf novae. We detected color variations within the early superhump
modulations making this only the second system, after V445 And, for which this
has been established. We carried out numerical calculations of the accretion
disk to explain both of the modulations and the color variations of the early
superhump. This modeling of the disk height supports the idea that height
variations within the outer disk can produce the early superhump modulations,
though we cannot rule out that temperature asymmetries may also play a role.
