  We report photometric and spectroscopic observations and analysis of the 2019
superoutburst of TCP J21040470+4631129. This object showed a 9-mag
superoutburst with early superhumps and ordinary superhumps, which are the
features of WZ Sge-type dwarf novae. Five rebrightenings were observed after
the main superoutburst. The spectra during the post-superoutburst stage showed
the Balmer, He I and possible sodium doublet features. The mass ratio is
derived as 0.0880(9) from the period of the superhump. During the third and
fifth rebrightenings, growing superhumps and superoutbursts were observed,
which have never been detected during a rebrightening phase among WZ Sge-type
dwarf novae with multiple rebrightenings. To induce a superoutburst during the
brightening phase, the accretion disk was needed to expand beyond the 3:1
resonance radius of the system again after the main superoutburst. These
peculiar phenomena can be explained by the enhanced viscosity and large radius
of the disk suggested by the higher luminosity and the presence of late-stage
superhumps during the post-superoutburst stage, plus by more mass supply from
the cool mass reservoir and/or from the secondary because of the enhanced mass
transfer than those of other WZ Sge-type dwarf novae.
