Keijo!!!!!!!!競女!!!!!!!! (Japanese); Hip Wip Girl; Hip Whip Girl (English)

From MangaHelpers: Kaminashi Nozomi (17) is an exceptional gymnast. So much so that colleges with some of the best gymnastic programs are trying to recruit her. Unfortunately for them, she has other plans. Due to her family being extremely poor, money is everything to her. That's why she wants to step into the world of "Keijo." "Keijo" is a type of gambling sport where girls stand on a small floating platform and compete against one another. The aim is to push the other contestant off of the platform into the water, but they are only allowed to use their butt or breasts to push the others off. Will Nozomi be able to compete in the intense world of "Keijo" and bring wealth and fortune for her family?