This story is a sequel to Horse People Go Naked
After a few disasters involving the resurgence of old enemies, the Princesses have seen fit that Equestria needs a bit of a reprieve to take their minds off of things. To that end, they have taken the suggestion of the resident human and introduced a new sport to the land.
Keijo, based off of the short lived anime, is a sport where women in swimsuits strive for dominance by knocking one another off of floating platforms and into the water. The catch? They can only use their boobs and butts!