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We present optical photometry of superoutbursts in 2016 of two WZ Sge-typedwarf novae (DNe), ASASSN-16dt and ASASSN-16hg. Their light curves showed a dipin brightness between the first plateau stage with no ordinary superhumps (orearly superhumps) and the second plateau stage with ordinary superhumps. Wefind that the dip is produced by slow evolution of the 3:1 resonance tidalinstability and that it would be likely observed in low mass-ratio objects. Theestimated 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-$q$ WZSge-type DNe: long-lasting stage A superhumps, small superhump amplitudes, longdelay of ordinary superhump appearance, and slow decline rate in the plateaustage with superhumps. The very small mass ratio and observationalcharacteristics suggest that this system is one of the best candidates for aperiod bouncer -- a binary accounting for the missing population of post-periodminimum cataclysmic variables. Although it is not clearly verified due to thelack of detection of stage A superhumps, ASASSN-16hg might be a possiblecandidate for a period bouncer on the basis of the morphology of its lightcurves and the small superhump amplitudes. Many outburst properties ofperiod-bouncer candidates would originate from the small tidal effects by theirsecondary stars.

ASASSN-16dt and ASASSN-16hg: Promising Candidates for a Period Bouncer