We report on time-resolved photometry of the 2015 February-March superoutburst of QZ Virginis .
The superoutburst consisted of a separated precursor , main superoutburst , and rebrightening .
We detected superhumps with a period of 0.061181 ( 42 ) d between the precursor and main superoutburst .
Based on analyses of period changes and amplitudes of superhumps , the observed superhumps were identified as growing superhumps ( stage A superhumps ) .
The duration of stage A superhumps was about 5 d , unusually long for SU UMa-type dwarf novae .
Using the obtained stage A superhump period , we estimated the mass ratio of QZ Vir to be 0.108 ( 3 ) .
This value suggests that QZ Vir is an SU UMa-type dwarf nova evolving toward the period minimum .
Based on the present and the previous observations regarding long-lasting stage A superhumps , a time scale of stage A superhumps is likely to be determined by the mass ratio of the system and the temperature of the accretion disk .