Ai to Yuuki no Pig Girl Tonde Buurin

On the way to school, Kokubu Karin, a junior-high school student, finds a piglet too hungry to move, so she feeds it. This pig is actually Prince Tonrariano III from planet Booringo. He gives Karin a transformation kit, consisting of a piggy nose, to reward her kindness. Karin puts on the nose and says the magical words that Tonrariano III taught her, to transform into the mighty flying super-pig, Buurin! But Karin is not happy to be a pig. Tonrariano III discusses the predicament with his father the King, who promises Karin that she can become her ideal super-heroine if she collects 100 pearls, which will be given to her one by one each time Buurin helps somebody. And so Buurin, the mysterious super-pig, appears from out of nowhere when people are in trouble, and helps them. Although everyone is curious of the pig's origins, nobody knows that Buurin is actually Karin... much to her relief. Source: AnimeNfo