The back-end theory
Video games have more than their share of, let’s say, unrealistically well-endowed female characters. The common refrain invoked in defense of these character designs is that the depictions of men as tall, trim, and muscled are no closer to the truth. Usually, the counterargument then proceeds to how the physical traits given to male characters are reasonable in most settings, while those given to females are have no such justification and can only be explained by sexual objectification, and so on.
I’d like to present Keijo!!!!!!!! as a different sort of rebuttal. It takes the “T&A is just the feminine version of buff” line of thought to its logical conclusion, by putting on shounen calling-your-attacks fights that exclusively use those breasts and buttocks. In this world, a woman can launch an opponent dozens of meters in the air with just her butt and the right training. This is, however, clearly not the case in reality. It follows that the aforementioned depictions of men and women are not unrealistic in the same way, at least not in the world we as the viewers live in.
So, yeah, QED or whatever.