  We present optical photometry of superoutbursts in 2016 of two WZ Sge-type
dwarf novae (DNe), ASASSN-16dt and ASASSN-16hg. Their light curves showed a dip
in brightness between the first plateau stage with no ordinary superhumps (or
early superhumps) and the second plateau stage with ordinary superhumps. We
find that the dip is produced by slow evolution of the 3:1 resonance tidal
instability and that it would be likely observed in low mass-ratio objects. The
estimated mass ratio ($q \equiv M_{2}/M_{1}$) from the period of developing
(stage A) superhumps (0.06420(3) d) was 0.036(2) in ASASSN-16dt. Additionally,
its superoutburst has many properties similar to those in other low-$q$ WZ
Sge-type DNe: long-lasting stage A superhumps, small superhump amplitudes, long
delay of ordinary superhump appearance, and slow decline rate in the plateau
stage with superhumps. The very small mass ratio and observational
characteristics suggest that this system is one of the best candidates for a
period bouncer -- a binary accounting for the missing population of post-period
minimum cataclysmic variables. Although it is not clearly verified due to the
lack of detection of stage A superhumps, ASASSN-16hg might be a possible
candidate for a period bouncer on the basis of the morphology of its light
curves and the small superhump amplitudes. Many outburst properties of
period-bouncer candidates would originate from the small tidal effects by their
secondary stars.
