An title inquiry actually

due to my pc suddenly BSODed on me many of my booked marked mangas are all gone [but thank you google chrom for letting me pick up where i left of >_<]

but some how its missing a few

most i know the title but there is this one manga i really would like to book mark again

well as for summary goes
"
its about a bread winner Girl who Entered a contest where the aim is to push the other contestant off the platform using nothing but their butts its currently a running series?
"

so would like some help here trying to get the title again....................

and actually realy if i have time Y_Y


so pls help me

An title inquiry actually