You find yourself transformed into a big fat anthropomorphic animal in a tight sumo diaper. (What animal are you? Or do you want it decided for you?) You're on the stage with another wrestler, a big fat walrus, who's been practicing for years. The winner of the battle gets to go free to their previous life, the loser has to stay transformed and trapped and has to practice sumo until they get to try another battle in a year. The battle begins.