Karin Kokubu rescues a yellow piglet on her way to school. The piglet turns out to be the prince of an alien planet, though, and turns her into the super-pig Buurin- but she'd rather be any other kind of hero.
Karin's school is having an important soccer match with a rival school, one known for their unfair tricks. Koichi, the star player of her school's team, is going to be the victim of these tricks unless Buurin does something about it.